Guide-lines for creating a simple chord-progression?

Question

I am working on a computer program that generates a simple melody, based on a simple chord progression of four chords taken from the 7 triads of the C Major scale. The program is also supposed to generate the progression. I was looking for an algorithm that will allow my program to discover chord progressions that sounds at least 'decent', and distinguish them from those that don't. However, as far as I understand, this algorithm doesn't really exist in a simple enough level. So what I'm asking, is for general guidelines for increasing the chance of knowing whether one chord is going to sound 'okay' (or even good) next to another chord in a progression. This way I can use these guidelines in my program, to lower the chance of two chords that don't sounds good together, be put next to each other in a progression.

Answer 1

Hi! How are you today? I hope you're staying safe at home!

There's a lot of great tools you can use to design your chord progressions. The most basic notion will serve you as a primer: the HARMONIC FUNCTION of chords.

Harmonic functions define the "need" each chord shows to move to another chord with a different function. In basic music, we think about RESOLUTION. This is, the need of a given chord to move to a TONIC chord (to "resolve").

For example, we can use the Natural Major Scale with the derived chords each of its 7 degrees provide and their harmonic function.

C Major scale: C, D, E, F, G, A, B....C

Degree chords in the scale:

Cmaj7 ( I ) TONIC

Dmin7 (II ) SUBDOMINANT

Emin7 ( III ) TONIC

Fmaj7 ( IV ) SUBDOMINANT

G7 ( V ) DOMINANT

Am7 ( VI ) TONIC

Bm7b5 ( VII ) DOMINANT

TONIC chords in a major scale ( I , III and VI chords ) are the "resolved" or "home" chords we need to arrive at the end of a progression. Their have NO HARMONIC WEIGHT.

SUBDOMINANT CHORDS ( II , IV )have LIGHT HARMONIC WEIGHT, with some "need" to resolve to a TONIC chord.

DOMINANT chords ( V , VII ) have HEAVY HARMONIC WEIGHT, so they have an "urgent need" to resolve to a TONIC chord.

The tool is: If you start your progression with any TONIC chord, use any SUBDOMINANT or TONIC chords in the middle and use any DOMINANT chord as the last in the progression before resolving to any TONIC again, you'll have a good progression.

As I said, this is just a very, very basic tool. We could talk for years about the infinite harmonic and melodic elements you can include in your compositions!

If you're interested in having lessons with me, please let me know! I teach all 8 levels of harmony and provide my students with really useful materials for each lesson. These include notions of all levels, ear training and other essentials!

Have a great night . Take care!

Carlos