How does one figure out chord inversions?

[BuddhaMaster]

Imagine you got a G Major song.
You play a Gmaj chord in the first inversion = B,D,G.

Just alone the fact that a Major chord / minor chord has got +4 respective +3 semis, and +3 or +4 semis in the second-to-third note remain after lifting the chord up an inversion. How the hell does anyone distinguish that from another chord and detect as an inversion, instead of simply another degree of the basic scale.

Do you detect it by the 3rd note, which has a higher gap between a inversion and the root chord, or how does anyone do that?

[sjm]

Well my simple answer to your example would be (and speaking purely as a self-taught musician): a chord is defined per se by the notes in the chord. B D G is G major because those are the three notes that make a G major chord. And yes that's pretty much what you're getting at with the intervals.

But the G major example is a bit misleading. I think what you're really asking is:
How do I distinguish between, say, am Em7 and a G6 (both have the notes E G B D) or, say, and Asus2 or a Esus4 (A B E)? After all, there are numerous chords such as these that can be given different names depending on how you look at them.

My simple answer to that would be "context". I'm sure that others here can provide you with more elaborate answer grounded in actual music theory as it is actually taught, but I'd say look for clues in terms of:

What is the bass playing - this might be played on another instrument of course! The bass note might give you a clue as to the root note - but it's not failsafe (a Cmaj7/B is still a Cmaj7, a walking bass is a walking bass etc.).

What are the other instruments playing?

What came beforehand, what comes next, what key are you playing in? Am Asus2 Asus4 Am would probably be more likely as a riff in a pop song than Am Esus4 Dsus2 Am if the song is in Am, especially if the rest of the music continues to be centred around the A throughout the riff.

What type of music is it? Certain types of music follow established standard progressions.



Things can get a lot more complicated if you're going to assume that not all notes in the chord are being voiced. This means that looking at what other instruments are playing might be key to understanding a chord choice. Your A B E chord could theoretically be a B7sus4 chord without the F#, for example, or your G B D could be part of an A11. It's uncommon to voice every single note in more elaborate chords, and in many cases is even physically impossible (e.g. not enough strings on a six string guitar to play all 7 notes in a 13th).

Personally - for simplicity's sake - I always write my chords in terms of what actually gets played - but I do this to document my own compositions exclusively, and doing so helps me remember what I was actually playing 5 years later.

But I often disagree on the names of chords with my colleague who is into jazz. She'll call a chord a 13th when I'd say it's just a 6th. A lot of it is just semantics and different conventions in different styles, at least IMHO.

[Nystul]

Without getting into the issue of multiple chords with the same name, you become familiar with these things through practice. When I studied classical piano, each week I would work on a major and minor scale and each scale had cadence chords. Let's say for example the scale was C major. With both hands I would play CEG, CFA, CEG, BDG, CEG. So that's I in root position, IV in second inversion, and V in first inversion. Very smooth sounding transition between the chords by using these inversions. Maybe jazz guys might do similar exercise with ii-V7-I. So by the time I had studied all 12 major scales, I had also studied each major chord in each inversion. And in the mean time I was learning actual music with actual chords in it. You do this sort of thing long enough and it becomes automatic.

[wrench45us]

generally because it functions as a G chord in context

[tapper mike]

We just do them and tend not to think about them as much as others would have you believe.

I know 13 different F7 chords from the first fret to the 13th. No extensions just the 7th. When one studies jazz and rock one usually studies chord progressions and melodies separately. Later if you wanted to develop a soloist style you might try to merge them.

In popular piano the goal is smart voicings moving from chord to chord using the shortest distance. So if you played a I-V-IV-V progression in C C-G-F-C
The right hand follows the shortest path C-E-G,B-D-G,A-C-F,B-D-G
On the guitar due to the way the strings are laid out the shortest path is often working thru barre chords because the hand doesn't have to travel as far to reach a fourth or a fifth.

Jazz stride does bounce around the keybed quite naturally but music of that era is mostly bygone. When you are studying jazz. pop, rock you really want to be locked into your zone without doing too much stretching. It's considered that you will be accompanying a vocalist or part of a small ensemble and if you play using a wide range you get into others zones. It's much easier to sing using a simple straight foreward rhythm/chord progression then it is to try and stretch your range.

Jazz generally doesn't call out inversions as it is in the hands of the performer not the sheet. A lot of chords are implied. Just because you see an F13 doesn't mean you play the whole chord. Maybe all you would need is an F6 or an F7, Earstwhile when you have simple structure chords you can expand them and pull off subsitutions.

Usually a teacher will put forth a standard then have the student play the piece as straight as possible. Then explain the subs and have the student try out various subsitutions. If you have a bass player who keeps the root on beat one it's pretty easy to get around. But once again, Joe still pulls off the root in the root. You have to get super sophisticated and explain how you'll treat a song to other musicians if you start subbing roots because they'll think your lost otherwise.



Pop/Rock on the otherhand is literal. And that's where you will see extended use of "Over" chords. Especially predominant during the 60's and 70's as walk downs and in the 80's the later as being more static.
A common walk down would be,,,, G F#/D Em G-B-G, F#-A-D, E-B-E

When dealing with pop/rock it's always best to get the sheet and analyze the actual harmony. Yes you could fake your way through it but it will sound less authentic. Sheet music isn't always accurate so it's a good idea to develop your ear as you develop your technique/reading.