Another music theory question (key of song)

[bullshark]

Ok, this is the way i would like the guitar player to play the Bm chord


But after the Em, I want him to "modulate into" (probably wrong to call it that, but I don't know how else to say it) like so:





Maybe I should just forget chord symbols and just write the notes on the score?

[Sascha Franck]

Nah, just give it a go. Probably show it to him and otherwise let him play it just the way he likes. Tell him to do some hammerings on the Bm or whatever. I woldn't try to limit him too much in the first place.

[bullshark]

True that, better to let the guitar player be...the guitar player.

Thanks for all the help Sascha, and do let us know when the book is out (I'd love a French version too if at all possible, there's so very little choice in books about music theory in French and they're all either too childish or too advanced, no middle ground at all).

[bpgeez]

Is it possible to know the key of a song with just the chord progression?

Say you had the chord progression: Bm-Em-G-F#, would that be enough to know what key you're in?

I would guess the key to be Bm, but I would only be guessing...an uneducated guess at that.

The progression is in the key of D major (6, 2, 4, 3). A very good reference that is very useful for determining keys is "The Chord Wheel" by Jim Fleser. Runs only about 10 bucks, and is very handy. Otherwise, by breaking down all the notes in the chords, you will find that they fit into the D scaling.

[sammy24]

Alright, now, all of a sudden, you may find a progression going Cmaj7-A7-Dmin7-G7. What the heck is up with the A7? Are we in the key of Dmin or something? The answer is no. It's just some "intermediate" (secondary) dominant to have some more guide tones resolving properly into the Dmin chord (the C# used in A7 will nicely resolve to D).

I would agree that the general key is definitely still C. But the A7 is definitely a momentary change to the key of D (usually D minor). Meaning, the A7 is functioning in the key of C, because it is pointing to the II minor chord in the key of C. (That is really all functioning means; that certain chords point to a tonality in a given context. G7 functions in C because it points to C as the tonality or key.) But the chord is still in the key of D, no matter how you slice it. These momentary key changes are happening all the time in jazz. So the melody will often stay diatonic, often through many momentary key centers, and you could sing it without any accompanment and it sounds like the key of C. But the harmony can be shifting to other momentary keys. This interplay between the horizontal aspect and vertical aspect can be a little confusing.

For one thing, since A7 is an unstable dominant chord, it doesn't have the affect of removing your tonal basis from the key of C. And then, it resolves to the chord Dmi7, which really has a double-function; it's acting as a momentary I minor chord, as it just came from its dominant A7. But really, it sounds like the II minor in C, because the ear remembers the key of C very well, so it just jumps back to being in C again. As an example of this, try playing the blues in C (minor blues scale, C-Eb-F-F#-G-Bb) over different dominant chords. You don't have to keep modulating, you can just stay in the key of C. This would seem to be because the unstable dominant chords do not force the melody into a new key.

If, however, the progression resolves to a major or minor chord (that's not diatonic to C) such as D7 going to G major, or A7 going to D major, or Eb7 going to Ab major or minor, then you will definitely have moved completely to a new key. This modulation will probably also be "momentary", meaning eventually the song will move back to the original key. But functionally it wouldn't be in key of C during those changes.

[Km7]

The progression is in the key of D major (6, 2, 4, 3). A very good reference that is very useful for determining keys is "The Chord Wheel" by Jim Fleser. Runs only about 10 bucks, and is very handy. Otherwise, by breaking down all the notes in the chords, you will find that they fit into the D scaling.

Geez...

[C00kie]

The progression is in the key of D major (6, 2, 4, 3)

No, definitely in B minor: 1, 4, 6, 5.

Why a progression that doesn't even contain the tonic? Have you played it btw? Where do you feel the tonic should be? ANd how does D major relate to that?

by breaking down all the notes in the chords, you will find that they fit into the D scaling.

... which is the same scale as B Minor: Q.E.D!

[Sascha Franck]

Wow, what a bump for this old thread...

- Sascha