A harmonic sequence is a chord progression which repeats a pattern in ascending or descending steps. The most common example is one in which each successive chord is a fifth below or a fourth above its predecessor. Here is an example in A minor:
Am Dm G C F Bdim E Am
So that’s A up four to D up four to G up four to C up four to F up four to B up four to E up four to A, at which point it has gone full circle. The reason why, in this example, some of the chords are major, some are minor and one is diminished is because only notes from the A minor scale have been employed. The sequence does not have to go full circle and usually it does not.
Harmonic sequences had their hay day in the Baroque period, although there are plenty of more recent examples, as you’ll see below.
But first, here’s a short piece for guitar which demonstrates the sequence shown above. Have a listen:
And, in case you want to play this yourself, here is the score:
So, how are harmonic sequences used in contemporary music? Here are some examples I’ve managed to track down:
Autumn Leaves (Eric Clapton version) – Em A Dmaj7 Gmaj7 C#m7 F#7 Bm B7
I Will Survive (Gloria Gaynor) – Am Dm G Cmaj7 Fmaj7 Bm7b5 Esus4 E
Hotel California (Eagles) – Am E7 G D F C … Dm E7 (a different type of sequence in which pairs of chords, the second in each pair a fourth below the first, descend by intervals of a tone)
If you’ve not tried these progressions before then take a look because you’ll find them a useful stimulus for new ideas.
