The Rolling Stones have reunited with former bassist Bill Wyman on some new tracks, and for a good cause.

"Boogie 4 Stu" is a charity compilation of sorts, organized by rock 'n' roll pianist Ben Waters, and he's brought in some of his good friends for the dance. Rolling Stones' Keith Richards, Ronnie Wood, Mick Jagger and Charlie Watts, plus Wyman and PJ Harvey have all contributed covers, standards and tracks to the set.

So who's Stu? That would be the Stones' late pianist, co-founder and tour manager Ian Stewart, who passed away in 1985 from a heart attack. Proceeds from the sale of "Boogie" will go toward the British Heart Foundation.

Below, we stream the Stones' cover of Bob Dylan's "Watching the River Flow" (featuring Wyman). Below that, there's a rotating sampler of the 11 tracks, including a sultry clip of Harvey trying out "Lonely Avenue."

"Boogie 4 Stu" is out on April 19.

The Rolling Stones haven't unleashed many previously unreleased tracks as of late, with exception to the spare deluxe tracks on the "Exile to Main St." remaster, out last year. There were rumors of a Stones tour for 2011, but as the summer is impending, there's been no luck in seeing confirmed dates.

Watching The River Flow by Eagle Rock