Perhaps music's most loyal fans, jam-band connoisseurs will eagerly accept nearly any music style from the groups they've chosen to follow. The Maryland-based quintet O.A.R. (Of a Revolution) updates the Latin/reggae aesthetic that permeated the early work of Phish and the Dave Matthews Band, seeming approachable even in comparison with its more prolific and popular predecessors. Building on the omnipresent buzz of online music trading and a relentless touring schedule -- two staples of the jam-band music-industry model -- O.A.R. has gone from being a high-school basement band to a college-rock sensation. As the title of its double-disc live release Any Time Now suggests, even wider notoriety appears to be right around the corner.