I played for about two and a quarter hours. I accomplished a few things: I discovered something about jazz chord sequences, and I wrote another tune.
I’ll start by talking about the jazz chord sequences. Some time ago, I searched the Internet for “common jazz chord sequences.” I found one that I liked:
CM7 CMm7 FM7/C FMm7/C | B♭M7 B♭Mm7 E♭M7/B♭ E♭Mm7/B♭ | A♭M7 etc.
Here are the functions of those chords:
- IVM7 in second inversion,
- IVMm7 in second inversion which modulates to a VMm7 chord,
- resolve down to the new IM7 chord, and then
- go to step 2 (repeat ad infinitum).
But what I realized today is that it’s a simplified version of the ubiquitous iim7 VMm7 IM7 jazz chord sequence. It’s just missing the iim7. And when I realized that, I thought that maybe the ii V I itself might be a compressed version of a more elaborate, expanded chord sequence. So I messed around on the piano, playing various chords in succession and deciding which ones sounded okay. I came up with a chord sequence where each chord is connected through just one note moving down a half step—
I’ve decided to call this the “expanded form” of the ii V I progression. There are probably other slightly different expanded forms, depending on what order you choose. I of course avoided any progressions that involved a minor 2nd interval because it sounds ugly, and I also avoided weird chords like the minor-major-seventh—but even excluding those situations, I’m sure there are many slight variations on this. I’ll have to think on it for a bit longer.
Here’s the “expanded” ii V I sequence in C. The chords are as follows:
CM7 CMm7 Cm7 | Am7♭5/C Cdim7 FMm7/C | Dm7/C Bm7♭5 | B♭M7
Separately, I came up with a tune that I thought sounded nice, so I recorded it. An interesting thing about this tune is that it ends with a modulation one fifth downwards (e.g., if it was in C then now it’s in F). I played it in the twelve keys for fun.
The chords (assuming it’s in C, which it begins in) are as follows:
||: CM7 FM7 :|| A♭M7 B♭M7 C9 | A♭M7 G♭M7 FM7