I am sure that when playing jazz chords which have extentions there are ways to cut down on thinking time in "live" situations. Having to play #11 on a chord and thinking ...where is root, count up 4 and sharpen it....is not going to work spontaneously. Especially when there are more than one extention and maybe several after each other.Which mind shortcuts are there, to cut out the thinking time?
Pretty well as you (and the rest of us) learned the basic chords!
There's really not much more to learn. When we did the 'basics', we had maj., min., 2 or 3 7ths - and their shapes sometimes didn't seem related to eah other. So, a couple of ♭9, ♯9, ♯11 etc. shapes will keep you with enough to play to start with, just like when you started, a couple of major shapes did the job then.
You probably know and use those basic 4 or 5 shapes for the 'basics', so do the same ideas all over again.
You may decide to work out your own voicings for some, and that's where the homework comes in - counting up, but then establishing the new shape as 'yours'. It's fun, and frustrating at times, but working out which shapes not only sound good (with missing notes sometimes) but also which are easy to move from/to from other chord shapes.
No tricks, just practice. You spend hours practicing, reading and playing, and then you begin to associate the numbers with their musical meanings faster and faster.
What comes to these add-sharp-flat-911-foo-bar monster chord symbols, the whole thing feels weird. I thought that a jazz player is supposed to see "G7" and play something completely different that sounds interesting but performs a compatible harmonic function. Where's improvisation if all tensions have to be written out?
9 11 13 ... calculate minus 7 and we have 2, 4and 6
another trick is: I analyze dm7/G to reduce G479 ... imaging one triad above the other.
(I know this isn‘t 100% identical and maybe not absolut correct)
It also helps a lot if you have the chord progressions in your ear and in your muscle memory.
The best trick is:
A Keyboard Jazzer has his repertoire of licks and riffs in his hands. He doesn’t count the numbers of extensions and he recognizes the chord progressions by ear.
As a beginner you will need a lead sheet but the basic chords or even R.N.s will suffice. The extensions have to lay in the fingers and be playable/available unreflected. That’s improvisation.
Internalisation of the sound of the extensions is a huge help to being able to play them in real time. Not only will that allow you to audiate better and translate your thoughts into music, it will facilitate the usage of similar sounds as substitutes for improvisation.
Ideally, you should be able to read G7♯11 and know a bunch of ways to play it. And obviously, practice is the best way to get good at playing the right voicings. I suggest that you take time to practice how playing each chord feels to your hands and subconsciously linking it to how the sound makes you feel.
Practice is the big key to memorising the chord extensions. The more you play the chords, the more familiar they will become, and the better you will get at playing them.
In short, as your practice more and more, you eventually learn more and more of it by heart. You keep practicing all kinds of tunes and keys, so that you can recall more chords instantly. Eventually you start recognising and reading chord symbols as a whole
But you're right: There are also some short cuts:
- You do your homework and practice the particular tune upfront
- You skip some chords if things go too fast (eg only first chord of every bar)
- You learn what tensions you can ignore at first (Eg. when written C7b9#11, you can get away with playing a plain vanilla C7, but for a Dm7b5 you better don't ignore that diminished 5th.
- Learn an altered voicing, and if a V chord has so many tensions that you can't read them... then use that one :-).
These are short-cuts and might not always work so use your ears!
As soon as you can play what's on the page... start diverting from it :-). But always listen.