Well, kids, here it is—the DC Jazz Festival’s annual flagship event, the big plenary session—the free concert. Things are a little different this year, though: it’s not on the National Mall, as it has been every year before. And, it’s not all free.

Lisner Auditorium, on the GW campus, plays host this year. The afternoon concert, at 3:30 PM, is the free event. It’s another chapter of the festival’s Latin jazz showcase, this time featuring two additional flavors: Puerto Rican pianist Eddie Palmieri, who plays a hard-edged dance form that’s brash, dense, exhilarating and exhausting; and Brazilian trumpeter Claudio Roditi, who at his best can blow paint off your walls and make them weep at the same time. This is not a performance to be missed.

Still, the big guns come out for the ticketed event at 8:00. Roy Hargrove, already heavy on the festival’s schedule, takes a new approach by bringing his big band, which is itself new, but its 2009 recording Emergence was one of the most interesting straightahead albums of the year. Joining Hargrove is sultry vocalist Roberta Gambarini, another favorite of this year and years past, though she earns her keep with her flawless delivery and rhythmic invention. Then, of course, comes the headliner: Roberta Flack, the ‘70s breakout star who was discovered in a DC nightclub and recorded two of the biggest hits of the decade, “The First Time Ever I Saw Your Face” and “Killing Me Softly.” By all accounts she is as gifted at singing jazz as at the folk-tinged soul that made her a household name; even on the off-chance that that’s not true, however, do you really want to miss her?

Jazz at the Lisner takes place at the Lisner Auditorium, 730 21st Street NW. Free (3:30 show) – $30 (8:00 show).