I want to incorporate some funk informed playing into my vocabulary. I know about bands like earth wind and fire and the funkadelics james brown etc...

But i want to incorporate some more rock type of funk playing (think jamies cryin by van halen or various satch and vai stuff)

Where should I start?

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Alas for I am Jay! Reviver of very, very old threads!

Check out Parliament Funkadelic. They'll provide a ton of ideas from combining rock and funk. Also Bootsy Collins.

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I want the bomb
I want the P-funk!

My band is better than yours...

Oh yeah!!!! Funk baby!!!
Prepare to have your rythym playing take a huge leap forward man.
Here's some stuff for reference;
The Meters
Red Hot Chilli Peppers (Blood Sugar Sex Magic is FULL of neat funk chords)
Prince...yes PRINCE!!!! He's a genius and a fierce Funk player.
The Time
Tower of Power (kinda' soul/funk but cool nonetheless)
The key to Funk is to not overplay, lay back and find nook's and crannies in the beat. Also, the Drums and Bass are KING in Funk, stay outta their way and let them shine. The guitar becomes another percussion instrument in a way. To acomplish this, some guys (ie Nile Rodgers) record their guitars direct into the board ,and use the out of phese settings on their Strats to get that tone. Also, try triads instead of full chords, stab chords if you will. Learn some chord substitutions on the top four strings.
THE RIGHT HAND IS THE KEY TO FUNK GUITAR!!!!
Put on some Funk recordings, mute the strings with your left hand and try to play scratch rythym with the drums; on the beat, on the off-beats, 8ths,16ths,ect.
I find a clean tone, a good dose of compression, and the out of phase pickup settings on the guitar helps. Ease up on the reverb too.
If you have a Wah, throw that into the mix too.
Good Luck,
Ian