The Roots may not have technically been the first live band in hip-hop – shout-out to Stetsasonic – but hands down, they're the greatest. Drummer Ahmir Thompson (a.k.a. Questlove) and rapper Tariq Trotter (a.k.a. Black Thought) connected in the late 1980s, when they were classmates at a performing-arts high school in Philadelphia. From 1993 on, they recorded a string of acclaimed LPs with an expanded line-up that took the jazzy style of predecessors like A Tribe Called Quest in revolutionary new directions – stirring in funk, soul, psychedelia and art-rock influences as the years flew by. In 2009, after nearly 15 years of tireless touring, the Roots accepted a gig as the house band on Jimmy Fallon's new late-night show. This could have heralded a comfortable retirement – but instead they've somehow become even more prolific, releasing some of their most fearless music to date and jamming on national television with everyone from Bruce Springsteen to Prince.