By far the best thing about Jimmy Fallon's late-night talk show replacing Conon O'Brien's was someone's decision not only to make The Roots the house band, but to expand the group's role beyond the standard intros and outros and backup of guest artists. Drummer ?uestlove, rapper Black Thought and the rest of the Roots crew are included in skits like Fallon's faux soap opera, "7th Floor West," and broader musical workouts like the improv game of matching a phrase and musical style from the audience and turning the band loose.

Before Fallon premiered, it was an open question which way this was going to go. Would such comparatively lavish mainstream success and the strictures of pop-culture television (even after midnight) dull the edge of the greatest (and not just because the competition is so scarce) hip-hop band in history? Or would the added lucre and celebrity  coupled with the steady work of the gig boost the band's confidence and acumen?

Watching ?uest and Black Thought tear it up at a one-off DJ show (?uest worked the t-tables and BT mixed freestyle with old raps), it was already apparent that group members wouldn't coast on their creativity and default to routine as a result of the hire. Now that Fallon has a slight hiatus, The Roots will prove as much to new recruits to their sound as well as hip-hop heads who have been following them since they came out of Philly in the early '90s, via a First Avenue concert Thursday night.

The Roots were experiencing a fresh burst of innovation even before the Fallon connection. When I last caught the entire band in performance, on the 4th of July last year at Summerfest in Milwaukee (where they'll head right after First Avenue), it was the best of the dozen or so Roots gigs I'd seen, beginning with Damon Bryson (aka Tuba Gooding Jr.) playing the patriotic fife part on sousaphone to ?uest's martial beat. Material from their then-new triumphant CD, "Rising Down," was amply featured with a greater emphasis on the horns. The band also launched into incendiary rendition of Dylan's "Masters of War" (with Captain Kirk Douglas on guitar and vocals; here is the first of three parts from their 2007 show at Bonnaroo), and ?uestlove spoke from the heart in condemnation of the racist policies of ex-N.C. Sen. Jesse Helms, who had died earlier that day.

For this gig, expect some material from their forthcoming "How I Got Over," which has been described as their most spiritual, gospel-oriented disc yet. For irony's sake, here is The Roots performing "Here I Come" on Letterman a few years back.

The Roots at First Avenue, doors at 6 p.m., $30.