Time to do this blog's name justice. No vid (yet) but I finally have something to talk about on Jazz!
I can't believe it took me so long. But I finally 'get' the Coltrane change. I could never get a grip on what folks would mean if they told me "play coltrane changes over D." which thankfully never happened but it's still something I feel is important to know. Thankfully that switch has finally flipped.
All I did was look at two tunes: Tune Up by Miles Davis (he probably didn't write it) and Countdown by Coltrane. Then I looked at the first four bars of both pieces and tried to keep what my teacher once said about the changes in mind. He mentions that it's a substitute for I-VI-II-V-I changes that has you going through major related keys. I actually get that, but I didn't understand in what way the major relations worked because it's not immediately clear in Giant Steps, the tune everyone thinks of and references when it comes to the Coltrane change.
But it's actually quite simple! Again, looking at Countdown, the basic idea is you jump to each major third relation in a descending manner, implementing dominants before playing each related key. Sounds harder than it is, here's an example:
Dude tells you to play these changes on Bb.
Major related thirds to Bb are Gb and D. As a side note, major third relations are always in sets of three. In this example, by learning them in Bb you also know to execute the changes in D and Gb. Just the order is different.
So the goal is to go to Gb and D major keys in that order (remember, you're descending!) before landing on Bb again. In total you get:
Bbmaj7 - Db7 - Gbmaj7 - A7 - Dmaj7 - F7 - Bbmaj7
To be clear, and this is where I always got confused, the above is what you can play if you see a regular I-VI-II-V-I progression over Bb major. The slight variation in Countdown is where you would play Cm7 instead of Bbmaj7 in the example above. There's also one in Giant Steps where you play full II-V's to go to each major key, say for example Em7 A7 Dmaj7 instead of just the A7 alone. It amounts to the same though so I wouldn't worry about it.
I expect no one to get any of this, but I'm glad I got it off my chest because this is one switch I'm thrilled to finally have flipped. Now to practice (read: grind) until I'm fluent in all 12 keys.