Arranging a full song from "piano chords" is hard...
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- KVRist
- 70 posts since 27 Feb, 2018
Hello, I've been studying theory more and more, and I've been following some songs, I rewrite the progressions in my daw at the exact times but TBH the piano chords sound nothing like the song. I mean, the song has strings,bass,guitar,synth,appregiato,brass, all going on at once, are they all playing a different note of the chord?
for example, say I have a Emin7add9 chord, the notes are, E G B D F
Piano,
Strings,
Brass,
Synth pad
Arp
Bass
Guitar
Horns
These are my instruments and that chords going to play for like 3 seconds
how do I arrange it? Do I split one note per each instrument, or am I suppose to play multiple notes?
like, guitar is probably going to play a powerhord, am I suppose to play the same in strings,pad,brass as well? what about piano? lol
How would you guys arrange a simple chord system on all these instruments at the same time? Say you have 4 bars, all 4 bars play the Emin9, which notes would go where? lol
I havent done songs for a while but I'm guessing
Piano > two notes chords of the notes in the chord, like E D, or E F
Strings I guess follow the powerchord format?
Brass, I think one notes of the highest
Synth pad follow powerchords?
Arp up and down all the notes,
Bass playing E / B eights (1st and 5th of note)
Guitar E,B powerchord (1st and 5th)
So with all these I have
E & G playing on 4 instruments
an arp going up and down all four notes
Brass playing the 7th's and 9th's
piano just hiting different combinations of all notes
See like, is there any standard rule for arranging certain instruments?
for example, say I have a Emin7add9 chord, the notes are, E G B D F
Piano,
Strings,
Brass,
Synth pad
Arp
Bass
Guitar
Horns
These are my instruments and that chords going to play for like 3 seconds
how do I arrange it? Do I split one note per each instrument, or am I suppose to play multiple notes?
like, guitar is probably going to play a powerhord, am I suppose to play the same in strings,pad,brass as well? what about piano? lol
How would you guys arrange a simple chord system on all these instruments at the same time? Say you have 4 bars, all 4 bars play the Emin9, which notes would go where? lol
I havent done songs for a while but I'm guessing
Piano > two notes chords of the notes in the chord, like E D, or E F
Strings I guess follow the powerchord format?
Brass, I think one notes of the highest
Synth pad follow powerchords?
Arp up and down all the notes,
Bass playing E / B eights (1st and 5th of note)
Guitar E,B powerchord (1st and 5th)
So with all these I have
E & G playing on 4 instruments
an arp going up and down all four notes
Brass playing the 7th's and 9th's
piano just hiting different combinations of all notes
See like, is there any standard rule for arranging certain instruments?
- addled muppet weed
- 111304 posts since 26 Jan, 2003 from through the looking glass
it depends how big you want that part to sound.
for a clearer piece you might just have one or two instruments play the whole chord between them with maybe a couple of others adding notes in higher and lower registers.
for a wall of sound all the instruments playing as many notes as possible
it's a taste and aims thing. do what makes it sound like the song in your head.
for a clearer piece you might just have one or two instruments play the whole chord between them with maybe a couple of others adding notes in higher and lower registers.
for a wall of sound all the instruments playing as many notes as possible
it's a taste and aims thing. do what makes it sound like the song in your head.
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Mister Natural Mister Natural https://www.kvraudio.com/forum/memberlist.php?mode=viewprofile&u=164174
- KVRAF
- 2892 posts since 28 Oct, 2007 from michigan
no, there isn'tkanoharuayu wrote:Hello ... See like, is there any standard rule for arranging certain instruments?
you would want to "carve" space in the moment for each instrument to be heard - how to do that is usually a matter of trial and error
best of luck
expert only on what it feels like to be me
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- KVRAF
- 1791 posts since 17 Sep, 2002
Piano, Strings, Brass,Synth pad, Arp, Bass, Guitar, Horns...
All at the same time?!
Depends what you're trying to do. Even a big orchestra isn't necessarily going to have that many separate voices playing at all times. Stagger the notes, add rhythm, take away parts, imply certain notes by emphasizing others, etc.
I'd suggest googling voice leading. The chords aren't presented as such; rather, they are separate lines that work together in such a way that, when taken as a whole, suggest a certain chord progression or cadence. This stuff is more like guidelines than hard rules, however. You're going to see stuff like "no parallel fifths or octaves" or "don't change all notes at the same time" and you can safely disregard it, but enough people believe in these that it has sort of become a convention in itself.
If you have everything blast all at once, it might get muddy, and stuff, and sound like you're banging out block chords with a densely layered keyboard patch. When everything has the same note start and note end, it doesn't matter too much how you arrange it, because it will all start to sound like a synth patch.
So it's not about "which instrument gets which voice," it's more about "what role is each voice playing?" and then work from there. You might find you don't need synth and brass and piano and strings and guitar all at the same time to get a full, powerful sound (in fact, it could ironically have the opposite effect, as everything just becomes muddy and undefined the more you pile it on). Sometimes an element on its own is more powerful than all the layering you can throw at it; it depends on context and intent.
Think of instruments like characters in a story; if all the characters talk at the same time, it's harder to distinguish between them, and they begin to lose their importance as individuals. And with all the A-list characters we have access to via our computers, it's hard to resist putting every single one of them in each and every scene.
Spread notes out too. Maybe move that 3rd up an octave. Maybe don't play the root note with the low voice, to create tension or uncertainty. Maybe don't feel you need to include every note; sometimes leaving the 3rd out of a 7/m7/M7 chord can create a whole new tone that has the same message but a different delivery, for instance. Try to emphasize the specific notes of that chord, the notes that really set it apart. Let them know you picked THAT specific chord. Not a major, not a major 7th, but a major 9th in particular, for example; really ham up that 9th.
On the other hand, if it sounds good, it is good. So, as suggested above, trial and error is your friend. Don't let a bunch of strangers on the internet tell you what sounds good.
All at the same time?!
Depends what you're trying to do. Even a big orchestra isn't necessarily going to have that many separate voices playing at all times. Stagger the notes, add rhythm, take away parts, imply certain notes by emphasizing others, etc.
I'd suggest googling voice leading. The chords aren't presented as such; rather, they are separate lines that work together in such a way that, when taken as a whole, suggest a certain chord progression or cadence. This stuff is more like guidelines than hard rules, however. You're going to see stuff like "no parallel fifths or octaves" or "don't change all notes at the same time" and you can safely disregard it, but enough people believe in these that it has sort of become a convention in itself.
If you have everything blast all at once, it might get muddy, and stuff, and sound like you're banging out block chords with a densely layered keyboard patch. When everything has the same note start and note end, it doesn't matter too much how you arrange it, because it will all start to sound like a synth patch.
So it's not about "which instrument gets which voice," it's more about "what role is each voice playing?" and then work from there. You might find you don't need synth and brass and piano and strings and guitar all at the same time to get a full, powerful sound (in fact, it could ironically have the opposite effect, as everything just becomes muddy and undefined the more you pile it on). Sometimes an element on its own is more powerful than all the layering you can throw at it; it depends on context and intent.
Think of instruments like characters in a story; if all the characters talk at the same time, it's harder to distinguish between them, and they begin to lose their importance as individuals. And with all the A-list characters we have access to via our computers, it's hard to resist putting every single one of them in each and every scene.
Spread notes out too. Maybe move that 3rd up an octave. Maybe don't play the root note with the low voice, to create tension or uncertainty. Maybe don't feel you need to include every note; sometimes leaving the 3rd out of a 7/m7/M7 chord can create a whole new tone that has the same message but a different delivery, for instance. Try to emphasize the specific notes of that chord, the notes that really set it apart. Let them know you picked THAT specific chord. Not a major, not a major 7th, but a major 9th in particular, for example; really ham up that 9th.
On the other hand, if it sounds good, it is good. So, as suggested above, trial and error is your friend. Don't let a bunch of strangers on the internet tell you what sounds good.
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- KVRist
- Topic Starter
- 70 posts since 27 Feb, 2018
@funky_lime
Hey thanks for the advice, that definitely makes sense, I watched a few arranging videos on youtube after making this topic and they gave me similar advice.
@jancivil
I was thinking of like Brass/String/Piano players in a band format, and they wanted all their sounds to gel together, if they knew right off the bat "oh, I'm a string player, I play the top two notes" etc
for bass and guitar players, they have their own rules.
for Am
Bass usually plays root or 5th
Guitar usually plays Root and 5th.... (powerchord)
Piano must hit like 3rd and 5th or something
Then
Strings
Brass
Synth pad
For pop music, there must be certain notes out of the chords that high strings/brass/pad usually hit...
@mister natural
Thanks, carving space has definitly been a hard thing for me. I find it hard to fit more then 3 instruments playing the harmony (not leads) most of the time.
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I use to make music without theory, I knew basic chords and could get 3 to 4 instruments together, but I noticed my songs were really obvious when the chords are changing, like block piano chords, and the way the other songs I listened to arranged their songs, I could barely even hear the chords playing everything transitions into the next seemlessly
About alot of instruments playing at once
I think I hear, Piano,Guitar,Bass,Strings,Brass,Synth Pad all going around the same time here, TBH it's hard to make out the instruments
About arranging from piano chords is hard
https://rechord.cc/BaVzUR9ErKk
open both those links,
play the youtube video,
then press play on the chord button at the time the section changes / lead guitar comes in, specifically when you hear the girl say "ka" lol
These are the chords I found online for the pre, and chorus, and they match sonically when played same time, if you listen to the song by itself, you can barely even tell the chords are changing, like, I would of never figured out those chords or how many chords are being used by myself here... Like, it's confusing but I would like to make songs that transition seamlessly like this, instead of obvious block chord songs, and I'm not sure what notes or what their doing, but I'm guessing their staying in within the chord notes per each bar? lol
Hey thanks for the advice, that definitely makes sense, I watched a few arranging videos on youtube after making this topic and they gave me similar advice.
@jancivil
I was thinking of like Brass/String/Piano players in a band format, and they wanted all their sounds to gel together, if they knew right off the bat "oh, I'm a string player, I play the top two notes" etc
for bass and guitar players, they have their own rules.
for Am
Bass usually plays root or 5th
Guitar usually plays Root and 5th.... (powerchord)
Piano must hit like 3rd and 5th or something
Then
Strings
Brass
Synth pad
For pop music, there must be certain notes out of the chords that high strings/brass/pad usually hit...
@mister natural
Thanks, carving space has definitly been a hard thing for me. I find it hard to fit more then 3 instruments playing the harmony (not leads) most of the time.
------------------
I use to make music without theory, I knew basic chords and could get 3 to 4 instruments together, but I noticed my songs were really obvious when the chords are changing, like block piano chords, and the way the other songs I listened to arranged their songs, I could barely even hear the chords playing everything transitions into the next seemlessly
About alot of instruments playing at once
I think I hear, Piano,Guitar,Bass,Strings,Brass,Synth Pad all going around the same time here, TBH it's hard to make out the instruments
About arranging from piano chords is hard
https://rechord.cc/BaVzUR9ErKk
open both those links,
play the youtube video,
then press play on the chord button at the time the section changes / lead guitar comes in, specifically when you hear the girl say "ka" lol
These are the chords I found online for the pre, and chorus, and they match sonically when played same time, if you listen to the song by itself, you can barely even tell the chords are changing, like, I would of never figured out those chords or how many chords are being used by myself here... Like, it's confusing but I would like to make songs that transition seamlessly like this, instead of obvious block chord songs, and I'm not sure what notes or what their doing, but I'm guessing their staying in within the chord notes per each bar? lol
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- KVRAF
- 1791 posts since 17 Sep, 2002
Regarding the song you linked: That fluid change is because of good voice leading. Notice how the bassline doesn't just hit the root or 5th, it sort of flows into the next bar fluidly, so that there isn't this "blocky" jump. You have to guide the listener into the changes, so to speak. Don't just yank them from one chord to the next; give them hints and suggestions by having your voices lead into the next chord before it all comes together. Maybe have some voice resolve into it on the second beat or something; stagger the timings, or else it will end up sounding like block chords.
The instruments don't just hit a note and hold it; there are subtle transitions or notes that are held while the others change.
For instance, when going from C to F, try having something hold that C while the other voices change, since C is in both chords you are using. Try using various inversions of the chords so that you can accomplish this. Or, alternatively, maybe try using a passing tone, possibly even some kind of chromatic interval (not necessarily in the scale), the beat before the next bar, to sort of "walk" the line from one chord into the next.
Instead of
CHORD - CHORD - CHORD
think
CHORD-to-the-CHORD-to-the-CHORD
---
Regarding conventional arrangement, well... there are all sorts of conventions for various genres (like violins tend to play the highest note) but they are more trends than actual rules. Try not to think in terms of "X normally does Y" but instead just play around and practice and experiment and learn what sounds good. Because conventions can get boring, and you shouldn't necessarily limit yourself to write in the exact manner that someone else did.
If you really want to understand these conventions, the best way is to listen to music analytically and transcribe it yourself (or find a score/tab/MIDI and really analyze it, if you can't transcribe it yourself). Find stuff you like and break it down. Play it back slow if you have to. Try transcribing a small snippet, a few bars or whatever, and then maybe check your work by looking at a score/MIDI afterward. It takes a lot of time and effort, but it will be a far better learning experience than posting on a forum about it. This can help you understand the idioms, conventions, typical ranges and use cases for various instruments and articulations, and the "tricks" that various artists use that makes them unique. But you have to put a lot of hours in to learn this stuff.
Alternatively, just keep experimenting, and do what sounds good to you. There really are no rules, just suggestions and observations
The instruments don't just hit a note and hold it; there are subtle transitions or notes that are held while the others change.
For instance, when going from C to F, try having something hold that C while the other voices change, since C is in both chords you are using. Try using various inversions of the chords so that you can accomplish this. Or, alternatively, maybe try using a passing tone, possibly even some kind of chromatic interval (not necessarily in the scale), the beat before the next bar, to sort of "walk" the line from one chord into the next.
Instead of
CHORD - CHORD - CHORD
think
CHORD-to-the-CHORD-to-the-CHORD
---
Regarding conventional arrangement, well... there are all sorts of conventions for various genres (like violins tend to play the highest note) but they are more trends than actual rules. Try not to think in terms of "X normally does Y" but instead just play around and practice and experiment and learn what sounds good. Because conventions can get boring, and you shouldn't necessarily limit yourself to write in the exact manner that someone else did.
If you really want to understand these conventions, the best way is to listen to music analytically and transcribe it yourself (or find a score/tab/MIDI and really analyze it, if you can't transcribe it yourself). Find stuff you like and break it down. Play it back slow if you have to. Try transcribing a small snippet, a few bars or whatever, and then maybe check your work by looking at a score/MIDI afterward. It takes a lot of time and effort, but it will be a far better learning experience than posting on a forum about it. This can help you understand the idioms, conventions, typical ranges and use cases for various instruments and articulations, and the "tricks" that various artists use that makes them unique. But you have to put a lot of hours in to learn this stuff.
Alternatively, just keep experimenting, and do what sounds good to you. There really are no rules, just suggestions and observations
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- Boss Lovin' DR
- 14312 posts since 15 Mar, 2002 from the grimness of yorkshire
All of the above..plus - whatever instrument and/or genre you're doing will have it's own conventions and styles.
Using guitar as an example, a folk player is going to approach the same chord sequence in an entirely different way than say someone doing Motown style stuff - the former will be mostly likely ringing chords with passages of picking; the latter more staccato rhythm stuff accentuating different elements, to simplify a little. Once you decide on what approach you want to take then that will dictate to a certain extent which notes will play when, so it might be also worthwhile looking at some of the more common rhythmic techniques for some of the instruments. Of course there's nothing to stop you then mixing it up a bit....
Using guitar as an example, a folk player is going to approach the same chord sequence in an entirely different way than say someone doing Motown style stuff - the former will be mostly likely ringing chords with passages of picking; the latter more staccato rhythm stuff accentuating different elements, to simplify a little. Once you decide on what approach you want to take then that will dictate to a certain extent which notes will play when, so it might be also worthwhile looking at some of the more common rhythmic techniques for some of the instruments. Of course there's nothing to stop you then mixing it up a bit....
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- KVRist
- Topic Starter
- 70 posts since 27 Feb, 2018
@funky
thanks again!!!! I didn't even know about voice leading, this seems like it'll help alot, and your explaination is really clear, I don't think I've ever kept a chord note going into the next bar, no wonder my stuff sounds so clunky lol
Passing tones and chromatic intervals, I have to look these up as well, so eventhough the song is transcribed as "this chord in this bar" you can hit a some off notes or such in the harmony so it transitions better? I gotto watch some videos on it. I've been planning on analyzing the midi files for a while just never got around to it because I wanted a better understanding of theory first (which I kind of have now lol)
thanks again!!!! I didn't even know about voice leading, this seems like it'll help alot, and your explaination is really clear, I don't think I've ever kept a chord note going into the next bar, no wonder my stuff sounds so clunky lol
Passing tones and chromatic intervals, I have to look these up as well, so eventhough the song is transcribed as "this chord in this bar" you can hit a some off notes or such in the harmony so it transitions better? I gotto watch some videos on it. I've been planning on analyzing the midi files for a while just never got around to it because I wanted a better understanding of theory first (which I kind of have now lol)
- KVRAF
- 26033 posts since 20 Oct, 2007 from gonesville
Well, you do seem to want this kind of thing as a truism, but it's not anywhere close to one, except that in the most simplistic cases a bass player may want to limit herself to something that uneventful. C&W or similarly super-simple types of music.kanoharuayu wrote: @jancivil
I was thinking of like Brass/String/Piano players in a band format, and they wanted all their sounds to gel together, if they knew right off the bat "oh, I'm a string player, I play the top two notes" etc
for bass and guitar players, they have their own rules.
for Am
Bass usually plays root or 5th
Guitar usually plays Root and 5th.... (powerchord)
Piano must hit like 3rd and 5th or something
[...]
What you want, though doesn't seem like very much FUN. You're hoping there is more paint-by-numbers aspect basically.
But find out what you want to sound like as modeled by the choices therein, break down what everybody's part was. That's what I did before I started arranging. I started as an arranger. For instance first thing was a singer's demo of a very Beatles-esque song. I took McCartney as the model for what I did on bass. I had sussed quite a bit of Abbey Road a couple three years before that so I 'got it'. Then he went prog rock and my business was freer and less prone to copy a model.
- KVRAF
- 26033 posts since 20 Oct, 2007 from gonesville
Why must there? Pop music, probably triadic or not a lot more than 4-note harmony; you have those 3 or more choices in that case. Why must there be no choice? Yes, having freedom can be overwhelming.kanoharuayu wrote:For pop music, there must be certain notes out of the chords that high strings/brass/pad usually hit...
Learn part-writing (voice-leading). There is no reason the violins writing has to be cut-and-dried except for laziness. All of this is contextual: what_is_your_idea.kanoharuayu wrote: instead of obvious block chord
- KVRAF
- 26033 posts since 20 Oct, 2007 from gonesville
What happened before the chord? What happens following it?kanoharuayu wrote: How would you guys arrange a simple chord system on all these instruments at the same time? Say you have 4 bars, all 4 bars play the Emin9, which notes would go where? lol
What's the melody in this spot if there is one?
What's the musical argument for a decision?
I'm not going to try and teach part-writing in comment boxes on the forum. funky lime indicated smooth voice-leading, such as common tones and so forth and suggested *an idea* but what's your idea?
You're in a hurry to take a smattering of information and run with it. It's still crawl-time. Analyze what you find attractive in an arrangement; I'll venture to state <take it off the recording until you finally have it> will develop your ear and give you more of a clue.
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- KVRist
- Topic Starter
- 70 posts since 27 Feb, 2018
Thanks for all the advice! I'll look up part writing as well, I didn't know about that either.jancivil wrote:What happened before the chord? What happens following it?kanoharuayu wrote: How would you guys arrange a simple chord system on all these instruments at the same time? Say you have 4 bars, all 4 bars play the Emin9, which notes would go where? lol
What's the melody in this spot if there is one?
What's the musical argument for a decision?
I'm not going to try and teach part-writing in comment boxes on the forum. funky lime indicated smooth voice-leading, such as common tones and so forth and suggested *an idea* but what's your idea?
You're in a hurry to take a smattering of information and run with it. It's still crawl-time. Analyze what you find attractive in an arrangement; I'll venture to state <take it off the recording until you finally have it> will develop your ear and give you more of a clue.
Definitely good advice to figure out what you want to sound like and break down the parts, I still plan on doing that, I just purchased 40$ worth of midi data off of a website (I know you can find for free) but these were like profressionally done lol I think this will help me understand how the intruments smoothly transition together, but even some midi songs sound horrible compared to the actual recordings.
I started music in 2012 with no prior knowledge, did about 40 full songs so far (instrumentals and stuff) half was before I knew theory, I get in these "research and apply" moods where I try to do everything and read up all the information at once so I can freely go about in the daw later without referencing...
I recently switched from FL STUDIO (where I literally would just write midi data) to playing keyboard in and using cubase with all it's features chord track and pads and such, and learning more about theory... I've been watching all the videos from the terms you guys helped me with so far in this thread and youtube has a lot of helpful videos covering them
I should of mentioned I'm mostly interested in Japanese / jpop / anisongs, but I'm not sure many ppl here listen to those genre, and there are many different musical styles in that genre by itself, but I mean the more "idol" and rock/pop "anime song" type of music, they usually use a lot of 7ths, some 9ths, min7b5's etc... and I wonder how they do their voice leading, which the midi files I bought should help with.
I thought what I was missing was the theory aspect of things on chords, but after learning the progressions I realized my weakness was in arranging the instruments properly lol
With the advice from this thread so far I learned the "don't move more than 2 semitone" rule which isn't a hard rule in voice leading, but works really well for smooth chords and other things, and one of my favorite transition chords is the V7 above the chord you're about to hit... also watched a video explaining that these pasing hords are often not included in transcriptions as well which may explain why I hear things in songs that seem like another chord before going into the next bar... so everytime somebody like you gives me a research word or advice it really helps me out lol I actually learned rythm on this forum a long time ago, somebody laid out the whole 1 n a 2 n a 3 n a 4 thing for me lol
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- KVRAF
- 7104 posts since 22 Jan, 2005 from Sweden
Things I struggled with is to kill the darling instrument - like guitar - and not let it play all the track through.kanoharuayu wrote: These are my instruments and that chords going to play for like 3 seconds
how do I arrange it? Do I split one note per each instrument, or am I suppose to play multiple notes?
like, guitar is probably going to play a powerhord, am I suppose to play the same in strings,pad,brass as well? what about piano? lol
Same with any other instrument.
Things tended to just be stacked on top of each other - sooooo wrong.
Let things come and go.
Piano chord maybe sound half a bar, then let some other instrument take on after on next bar or so.
Listening to production I like a lot - Frankie Goes to Hollywood and Welcome to pleasuredome - I learned that.
It becomes so much more interesting to listen too - different things happends all the way through.
- KVRAF
- 11162 posts since 16 Mar, 2003 from Porto - Portugal
There is a story I usually tell people (this is a true story - it actually happened). A guy I know was once hired to produce an album. On one of the songs, he just added an acoustic guitar accompaniment. The guy who hired was dissatisfied, and told him that he wasn't paying him to just come up with an acoustic guitar accompaniment. To which he replied: "You are not paying me to ADD instruments, you are paying me to TAKE THEM OUT."
This seems like a joke, but to me it's all there is about arranging and producing. For example, the OP came up with the list:
All these questions are important, IMO. One of things I studied was Orchestration. We studied how the orchestra was treated in different hitorical periods, and how a piano piece (usually of that period) would be orchestrated. Arrangement is pretty much this - you have the skeleton (which is your "piano chords") and you want to "dress it", adding the organs, the different systems (the blood circuit, the digestive circuit, the respiratory circuit - not use how these are correctly designated in english) and finally cover all this with a skin.
Basically, there are no absolute rules (assuming there are any rules at all). Listen to songs in the style you like and want to mimic, and try to devise what kind of instruments they use, and how they use them. And don't think that the bass will always have to play the fundamental of the chord, or that it even has to play just notes from the chord - try to create "parts" for each instrument that (ideally) survive and make sense on their own. If you are writing the strings part, it should sound good and make sense on its own, without anything else. The same for the bass, for the brass (when they come up), etc.
And bear in mind that the same song (chord structure) can be a baroque piece, a solo piano piece, a symphonic piece, a folk song, a heavy metal anthem, a pop song, etc., depending on how you dress it.
This seems like a joke, but to me it's all there is about arranging and producing. For example, the OP came up with the list:
I would ask: Why? Why these and not others? Why not just a few of these? What do you think THAT song asks for? What kind of "sound" or "style" do you want to achieve?kanoharuayu wrote: Piano,
Strings,
Brass,
Synth pad
Arp
Bass
Guitar
Horns
Piano
All these questions are important, IMO. One of things I studied was Orchestration. We studied how the orchestra was treated in different hitorical periods, and how a piano piece (usually of that period) would be orchestrated. Arrangement is pretty much this - you have the skeleton (which is your "piano chords") and you want to "dress it", adding the organs, the different systems (the blood circuit, the digestive circuit, the respiratory circuit - not use how these are correctly designated in english) and finally cover all this with a skin.
Basically, there are no absolute rules (assuming there are any rules at all). Listen to songs in the style you like and want to mimic, and try to devise what kind of instruments they use, and how they use them. And don't think that the bass will always have to play the fundamental of the chord, or that it even has to play just notes from the chord - try to create "parts" for each instrument that (ideally) survive and make sense on their own. If you are writing the strings part, it should sound good and make sense on its own, without anything else. The same for the bass, for the brass (when they come up), etc.
And bear in mind that the same song (chord structure) can be a baroque piece, a solo piano piece, a symphonic piece, a folk song, a heavy metal anthem, a pop song, etc., depending on how you dress it.
Fernando (FMR)