I'd heard them separately as superlative improvising musicians - William with Matthew Shipp, Cecil Taylor and Charles Gayle; Hamid with Fred Anderson, Ken Vandermark and Adam Rudolph.
Then I heard O'Neal's Porch. It paired the two of them with alto sax player Rob Brown and trumpet player Lewis Barnes and they were billed as the William Parker Quartet. This 2000 recording had the drive, rhythm and melodic structure akin to traditional "modern jazz" (for lack of a better term) and the edge, openness and looseness of avant garde/free jazz (once again, for lack of better terms) - like a musical journey that took the scenic route, the back roads...
The concert we have here is taken from French radio (which accounts for a couple of the abrupt intros to pieces - The French radio hosts are the most obnoxiously verbose on the planet, bar none!). The performance is taken from 'Sunset', 60 Rue des Lombards, Paris on 24th April, 2009
It's now billed as the "William Parker and Hamid Drake Quartet" with William Parker (bass) ; Hamid Drake (drums); Rob Brown (saxophone); Lewis Barnes (trumpet). It is made up of three twenty-minute-plus pieces.
PS. There's seems to be some problems with this download. Hang tight. I'll re-up this file and post new link very soon! Thanks for the heads up!