Funk keyboard tricks of the pros... well, not "tricks" exactly. There's no "inside secret" that the professionals know and refuse to share with the rest of the world. But there is a little thing called "experience" - something the pros have and the advancing students need. Have you ever wondered why your playing doesn't sound as clean as on professional recordings? Or why your advanced jazz comping doesn't sound good on non-jazz tunes? Or perhaps you think your solos sound a little stale? If "yes," read on.
Let's first discuss clavinet and organ playing. Although they look like pianos, simply cutting and pasting left-hand-type piano voicings to the clav or organ generally doesn't sound good and means that you don't really understand the instruments.
The clav has a fairly small dynamic range. The very lows will sound muddy and distorted. The very highs will sound thin with quick decay and no resonance. So stay in the mid-range in order to keep the instrument in its wheelhouse. And keep your chords and comping s-p-a-r-s-e. "Less is more" means that you will get better-sounding chords if they are not too thick. Sometimes even single-note clav comping is the most effective. Pros understand that the clav is most effective when it is primarily used rhythmically instead of as a comping instrument.
The organ is incredibly expressive with a much larger range than the clav. But the "less is more" concept still holds true. The organ is great at creating a wide variety of textures with its different drawbar configurations. Chord voicings and comping requires different considerations than those at the piano. So don't approach chords the same way you would at the piano. Using fewer notes often yields the best result.
You probably practiced long and hard to learn your left-hand rootless voicings for jazz playing, right? Stuffed with 7ths, 9ths, 11ths, 13ths, and altered extensions, you figure there's so much cool stuff in there how could it not sound good, right? Well jazz harmony (and therefore jazz comping) is very different than funk and rock comping.
For rock music, try to revamp your approach to chords. Start by getting rid of all 7ths, 9ths, 11ths, and 13ths. Begin by using only triads in all possible inversions. It's pretty common to use 9ths in rock, and sometimes even 7ths, so slowly start adding those back in. Funk music is a little closer to jazz in its use of 7ths and 9ths (often sharp-9ths). But try using triads (even if they include extensions) instead of 4-note chords. You might find that the spacing in triads creates a better sound for funk-playing.
Ever hear a burnin' keyboard or guitar solo where the player all of a sudden goes into some "outside" key that seemingly comes out of nowhere and yet sounds awesome?
You've probably heard of the pentatonic scale. Well, when playing over a chord that stays put for a couple measures or more, it's a very cool idea to do what is sometimes called "side-stepping" - playing exactly one half-step above or below the key you're in. You're basically using all of the "wrong" notes. But because they're so close to the "right notes" (only a half-step away) they pull towards a resolution... and create a ton of awesome-sounding tension.