There’s a fine line between a jam band and a band that jams. New Orleans’ the Revivalists fall into the latter category. The group burst onto the scene in 2008 and honed their chops in 2009, expanding their live set as well as their songbook in the process. After spending some time in the studio, they return with Vital Signs, an album that brims with soulful melodies, explosive jams, and down-home rock ’n’ roll.

Singer Dave Shaw delivers an especially powerful performance here. His husky, fervent wail goes perfectly with the locomotive groove of “Ride the Earth,” a propulsive number whose lively acoustic breakdown and dancing sax fills calls to mind a more rocking version of the Dave Matthews Band. Earlier, his gripping rasp shimmers on “Strawman,” a tugging ballad with major crossover appeal.

Never showy or indulgent, the band tempers its virtuosity with calculated eruptions and nimble, intuitive punctuations. The racing atmospherics, winding guitars, and ricocheting rhythms of “Appreciate Me I” show why The Revivalists have also latched on with indie rock fans. Perhaps no song better captures the group’s inventiveness and creativity than “Soul’s Too Loud,” an intoxicating foray that emerges from a shadowy backbeat and a hypnotic guitar melody, only to be swept up into a collage of convulsive psychedelia.

The group does have a tendency to lean too heavily on their adolescent influences, sometimes pumping a little too much Nineties-alternative into their sound. Shortcomings aside, the Allman Brothers-flavored closer, “Hurricane Winslow,” lets you know that the next wave of Southern rock is in good hands.