Session guru Leon Russell has credits with everyone from Eric Clapton to Frank Sinatra, flanked by gigs with Phil Spector’s Studio group, and later his own Church Recording Studio. The probable origin of ZZ Top’s beard and 10-gallon-hat style, Russell is a master of blues-pop hooks, penning hits for Joe Cocker and The Carpenters that would later earn invites on George Harrison recordings. This tour will probably showcase more of his country side, the kind he used to light up the Billboard charts with Willie Nelson duets in the late 70s. (Gavin Paul)