Knowing what chord to play next?

Question

This is a question I've had for a long time but I've never really found the answer other than following some suggestions on chord sequences like 1,3,2,5 and 1,4,5, but I'm sure there must be another way of coming up with a sequence of chords that work together.

I usually write my melodies first and try to work out what chords work with it based on the notes I'm playing. Occasionally I try to write some harmonies first when I compose, but with either approach, I'll reach a point where I'm dumbfounded on where I can go next.

Let's take a simple example, I'm writing a comedy orchestral track now starts with C major, then goes to Gb major (essentially shifting key). I've written some lines on top of those chords, but now I can't find where to go next.

Is there any musical theory I should be drawing on to find out where to go next?

Answer 1

Nearly every melody line has underlying harmonies (chord) which reflect the notes in each bar. E.g., in a bar of C-E-F-G, there are notes which make Cmaj., so that chord will fit in that bar.

In a bar with, for example, an F and A, this will give you more scope - F, Dm, G₉ come to mind.

Often there's a note which won't fit a chord, and if it's on a weak part of the bar, it won't count towards that chord. Weaker parts could be 2nd or last beat, or maybe the 'and' between beats. 1st and 3rd (in 4/4) are places to look for components of a chord. When you move out of key, as in C - G♭, there are no common notes, so either change chord within the bar, or possibly use a B♭ note, which could fit both C₇ and G♭

Really need that sample.