Let's try a musical thought experiment:
Imagine that you're sitting down at the piano, and want to compose a tune. You decide that it's going to be a jazz ballad, and you choose the key of Bb major.
Hmmm... should it begin on the tonic chord, or somewhere else in the key? You decide to link your new creation firmly with the jazz tradition by beginning with a ii/V/I in Bb: Cm7 F7/Bbmaj7. And since you want it to sound "traditional-but-not-too-traditional, you put in a #5 as it arrives on Bb, making it a D/Bb harmony for a quick bit of dissonance or tension before resolving to the expected Bbmaj7 chord as an older composer like Gershwin would have done.
Now...where to go next?
Perhaps a still-traditional iim7(b5) V7/ i to the relative minor, Gm. Still could be something out of The Great American Songbook, and you've put in a nice, catchy melody to go along with the chord progression.
So far so good.
The Gm7 will proceed up a 4th, to C7, which is a strong harmonic choice. But in the back of your mind, a few doubts are lingering. "Does this sound too predictable?" "Is it boring?" "Do the chords sound too old-fashioned for what I'm aiming for?" "Will it challenge me enough as an improviser?"
So you decide to change things up a bit.
BAM! A sudden, surprising move to Bmaj7!
Colorful, and even shocking. And with no preparation or warning. Just go there!
Now we're talking!
OK, let's change up the way the chords move, by putting in a descending bass line: B A#, G#, F#, staying in the key of B major for a while. (heh heh... let's see how many pianists can solo over this!)
So.. how long should this tune be, anyway? Does every song have to be in a 32-bar AABA form? What if I make it very short? Musicians can still stretch it out during their improvisations. But the basic form can be very concise. What if it was only 8 measures long? Has anyone ever written a tune that short before? And does that even matter?
Well... it's 6 measures long already. I only need to compose 2 more bars and call it a day.
I know... I'll stay on F#, bring in a Lydian sound for something different, and then put into a basic turnaround to get back to Cm, which can lead everyone either back to the beginning again or serve as an ending chord.
A new tune, and I'll title it "Coral."
Well, I don't know if this is what pianist extraordinaire Keith Jarrett was thinking when he composed his brief masterpiece "Coral" during the early 1970s, but it does follow the tune fairly closely.
In just 8 brief measures, Jarrett managed to be both traditional and non-traditional at the same time, while bringing us on a journey to several key centers along the way.
"Coral" is a wonderful tune to play, and it's in The Real Book. Here's my version, which I hope will inspire you when you create yours.
Enjoy the journey, and "let the music flow!"
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