"A song is an organism that has a history and has different meanings to many different people," says Rusted Root lead vocalist-guitarist-songwriter Michael Glabicki. "Those people attach themselves to this organism and because of that, it's a ritual, a way to jointly go places." It's funny; the same can be said for Rusted Root. The Pittsburgh sextet evolved from a single cell into a musical organism of quintessential essence, monumental substance and vast appeal. Its fourth record, Welcome To My Party, is a further, astonishing progression; a distillation of chops and songwriting finesse revealing a distinct musical force. Produced by Bill Bottrell (Tom Petty, Sheryl Crow and Rusted's platinum When I Woke), Welcome… features eight compositions from Glabicki, one each from vocalists Liz Berlin and recent reenlistment Jenn Wertz, and opens with the funky, percolating "Union 7," the first ever 50-50 lyrical collab between Wertz and Glabicki. These songs capture the essence of a band that is truly a single, thriving organism.