From rockabilly to pop, rock and blues to jazz-rock, New Rhythm and Blues Quartet, NRBQ, can just about play it all. Founded by pianist Terry Adams in 1967, the band is known for its diverse sound and high-energy live performances. Recently Mr. Adams revamped the band’s lineup and has been as busy as ever, churning out two albums — one live, one from the studio — in the past two years. Another studio album is in the works. NRBQ returns to Martha’s Vineyard to play at Flatbread this Sunday, July 21, after a long time away from the Island.