This post is a musical note-to-self and a follow-up to my post on Charukeshi-Gopriya. Here, I’d like to provide mode detail on “note collapse,” an idea that I’ve begun to explore in my improvisational playing. If you read this post and try it out, please let me know what you discover.
First, a recap of “standard” modulation. When we modulate from a major key to the key a fifth above it (for example, C major to G major), we raise the fourth note of the original key by a semitone. The raised fourth then serves as the leading tone to the new root. All of the other notes remain in place, but assume a new “function” with respect to the shifted root:
But that’s only one way of “modulating” from one set of notes to another–there are lots of nonstandard modulation techniques to explore, particularly when we leave the diatonic system and work with less common scales. This post is about one of those many nonstandard possibilities.
I’ve been using the term “note collapse” to refer to a process of moving from a 7-note scale to a 6-note scale by taking two notes that are a whole tone apart and “collapsing” them into the one note that falls between them. I noticed that the Jazz Melodic Minor scale and each of its modes can be converted into the Whole Tone (WT) scale via note collapse. This process works particularly well for the fifth mode of Melodic Minor (Mixolydian b6). Here’s an improvisation that makes use of a repeating shift between between Mixolydian b6 and WT via note collapse (in a way, I hate to describe this piece so technically, because recording it was a strong personal experience and I wasn’t thinking technically at the time, but in fact the whole thing was made possible by a fairly technical idea):
What I’d like to do here is show how each of the modes of Melodic Minor can progress to WT via note collapse: fodder for improvisational experiments. Even if you don’t use note collapse as an improvisational idea, these diagrams might still be useful as a way of getting a grip on the “exotic” modes of Melodic Minor, as they show how each mode can be derived by taking a part of the completely symmetrical WT and expanding it (i.e. doing a note collapse in reverse, to turn one note into two).
In each diagram, the top line represents a mode of Jazz Melodic Minor and the bottom line is the Whole Tone scale. The red arrows show how two notes of the Melodic Minor mode would collapse into one note of the Whole Tone scale. There are a number of ways to label the notes of WT. In general I prefer labeling the fourth note as #4 rather than b5 because it often sounds to me like “a #4 reaching towards a 5 that isn’t there.” However, as the sixth Melodic Minor mode has a b5 in it, I preserve that labeling in the corresponding WT. The first two modes are problematic because we lose the root in the note collapse to WT. In those cases, I use b2 (instead of #1) in labeling the first note of WT, since I tend to think this WT would be used as an interlude where the original root has disappeared for a time but is still remembered.
In exploring the Melodic Minor modes I’ve learned a huge amount from Amit Chatterjee, and also from Tom Lippincott’s resource on “Melodic Minor Harmony” — available here.