It's a question that's a little ambiguous. Sly and the Family Stone and
the Parliaments were not co-founded by Sly and George Clinton, though George
has mentioned the influence that Sly's recordings had on him, particularly
A Whole New Thing. However, Sly has
appeared, in various ways, on P-Funk recordings. For example:
P-Funk All-Stars' 1983 album Urban Dancefloor Guerillas
featured "Catch a Keeper," co-produced and arranged by
Sly, with vocals from Sly, also "Hydraulic Pump"
co-produced by Sly, with Sly on keyboards, organ/synth, and
vocals. Both songs were co-written by Sly.
Cover of "If You Want Me To Stay" on Clinton-produced Freaky
Styley by Red Hot Chili Peppers.
Clinton mentions "Slick and the Family Brick" during
"Let's Take It to the Stage."
Mentions of Sly on Standing on the Verge of Gettin' It On's
Wet Epic Debauchery and on Bootsy's What's Bootsy Doing?.
Cover of "You Can Make It If You Try/Thank You" on P-Funk
All Stars LIVE.
Cover of "Thank You" on Maceo & the King's Men
Tracks with Sly performing on Clinton Family Series Vols. I and IV.
Bootsy throws in a vocal riff that Sly used when performing "If You
Want Me To Stay" into the chorus on his song "Under
The Influence Of A Groove." (Thanks to Prashant Gopal).
Sly toured briefly with George Clinton and P-Funk in the early 80's,
and Sly & the Family Stone opened for P-Funk during the late 70's.
I think it's purely subjective as to whether or not Sly is part of P-Funk,
though there are more than enough instances to associate the two.
To see what George Clinton, Bootsy and P-Funk are all about, check out
Rob Clough's Motherpage .