To the specific question of "What chords would go good with a melody", there are a number of factors to the answer.

But first, you need to know what chords are in the key.

This requires that you know the key that you're in.

Once you know the key, you need to know the notes of the scale. For example, the notes of the D major scale are (D, E, F#, G, A, B, C#). The notes of the F major scale are (F, G, A, Bb, C, D, E).

Once you know the notes, you can create a list of chords in the scale. The 1st, 4th and 5th notes of a major scale will always give you a major chord. The 2nd, 3rd and 5th will give you a minor chord. The 7th note will give you a diminished chord.

So if you're in the key of D major, you have the chords:

D (D, F#, A)
Em (E, G, B)
F#m (F#, A, C#)
G (G, B, D)
A (A, C#, E)
Bm (B, D, F#)
C#dim (C#, E, G)

Again, I assume you already know this.

OK, now on to the "rules":

1. Most importantly: No matter what the "rules" tell you, if it sounds good, it is good. And if it sounds bad, it is bad.

2. Typically, only "important" notes need to match with the chords. If a note isn't on a strong beat (1st or 3rd beat), or is short, it's OK if that note doesn't go with the chord. A little bit of dissonance makes things interesting.

3. A chord will go with a melody if the melody note is a member of the chord. So if you're in the key of D and have a C# note in the melody, any chord with a C# will sound good. Reworking the chord chart above, we get:

D -> D, Bm, G
E -> Em, C#dim, A
F#m -> F#m, D, Bm
G -> G, Em, C#dim
A -> A, F#m, D
B -> Bm, G, F$
C# -> C#dim, A, F#m[

So the chords C#dim, A and F#m will all sound good with the note C#. You don't really need to make a list, you can just find the chord based on the note you're looking at (C#dim), two steps under that note (A) and two steps over that note (E).

In contrast, the chord G won't work, because the G chord doesn't have a C# note in it - the notes of the G chord are (G,B,D).


This raises the question, "What chords go with other chords?" The answer is "it depends", but in general:

1. If the chord is 3 scale degrees higher than the prior chord, it's strong and smooth. So a D chord will strongly follow a A chord, because D is 3 scale degrees above A: (A,B,C#,D). Similarly, Bm will follow an F#m.

There's a handy diagram called the "Circle of Fifth" or the "Cycle of Fourths" that Google will happily find for you. Learn it and love it.

2. If a chord shares two notes of the prior chord, it'll sound smooth. So a D chord with the notes (D,F#,A) will connect smoothly with a Bm chord containing (B,D,F#), because they share the two notes (D,F#).

3. If the chord is a major and belongs to the key, it can move to any other major chord in that scale. For example, the key of D has three major chords: D, G and A. So any of these chords will smoothly follow each other.

-- David Cuny
My virtual singer development blog

Vocal control, you say. Never heard of it. Is that some kind of ProTools thing?