Only saw him once but very entertaining and talented
YouTube - George Harrison & Friends 1971 : "Jumpin' Jack Flash Medley" LEON RUSSELL (http://www.youtube.com/watch?v=ce_Z9NuwVBY&feature=related)

another favorite

YouTube - Leon Russell -- Back to the Island (http://www.youtube.com/watch?v=r7MoZuP3JBo&feature=related)

And how many artists have recorded this one he wrote...but does not own the rights to....

YouTube - Leon Russell- Song For You (LIVE) (http://www.youtube.com/watch?v=6UQLFiDH1lA&feature=related)

he wrote This Masquerade, beautiful tune that Benson just burns through..

YouTube - George Benson singing "This Masquerade" (http://www.youtube.com/watch?v=RpEfAV1T5b0)