Given a riff, how do you find a suitable chord progression to it?

Question

I wonder how the professional or seasoned songwriters do when he came up with a melody and tried to find a suitable chord progression along with it. I am not that new to song writing. For a riff of the Pop kind often times I can easily attach a proper chord progression to it. However, when I came up with a more intricate riff, then it seems that at this stage I could only use a chord progression sounding far-fetched here and there. (My major songwriting instrument is guitar, sometimes keyboard).

For concreteness I guess an illustrative example would suffice :). I realize doing this is an art instead of an engineering process that has got an SOP something.

Answer 1

I would recommend a thorough study of major, harmonic minor and melodic minor modes. https://en.wikipedia.org/wiki/Mode_(music) Most melodies that you create will be in a particular mode for some or all of the riff. Once you are familiar with the modes and the chords that are native to each mode, you will be able to instantly think of some chord options to play over the prominent notes of the riff.

Also, I would recommend a thorough study of jazz chords. https://en.wikipedia.org/wiki/Jazz_chord

Answer 2

Once a musician is familiar with improvisation and composition, the brain processes what happens (like finding the harmony for a riff) automatically. If we had to dissect the major steps of how musicians do it, then we could come up with some rough steps like this:

1. Break the riff into chunks (measures or beats)
2. Analyze which notes are in which chunk
3. The harmony of a particular chunk of the riff would be determined by which chord the notes are closest to.

In pop, melodies are pretty straightforward, so it would not be challenging to relate a set of notes with a chord. For example, a melody chunk of "C D F E" would be associated with C major, due to having two notes of the chord, and also starting with the root (lowest note of the chord), or C.

However, in other genres, such as jazz, modern, or classical (which I compose), it depends more on the "feel" of the musician. In pieces that I compose which borders tonality and atonality, sometimes the chords match my melody, sometimes they are completely unrelated, and sometimes the harmony has dual-tonality!

Overall, there are some automatic steps that musicians unconsciously go through, but we don't think about them, and just write down whatever comes into our heads.

Answer 3

Understand theory and the riff. Play the chords over the notes that represent the riffs. That simple. If you like you know it sounds good.