Last year’s Revelator marked the arrival of an American roots music powerhouse: the Tedeschi Trucks Band. Assembled by Gibson SG-playing dynamo Derek Trucks and blues singer/guitarist Susan Tedeschi – popular music’s most soulful married couple – the group has cut a broad, worldwide swath through the realms of blues, rock, soul, gospel and even jazz since first taking the stage. And for good reason. Large ensembles of earthy top-notch players like the 11 musicians in the Tedeschi Trucks Band haven’t existed since the ’60s and early ’70s, when Delaney and Bonnie Bramlett led Delaney & Bonnie & Friends, and Joe Cocker fronted the Mad Dogs & Englishmen.