The motto for the Mid-Atlantic Jazz Festival, “Standing Up for Real Jazz,” smacks of rigid definition—the Jazz-as-Ideology school. But festival curator Paul Carr doesn’t just wave the banner of purism: He builds a case for it. The first day alone features 21 different performances of solid, swinging, straight-ahead jazz. They run the gamut from middle-school combos to acclaimed veteran headliners—the latter in most cases being singers, the special emphasis of this year’s festival, now in its fifth go-’round. That includes local favorites Kristin Callahan and Heidi Martin as well as international stars Giacomo Gates and Freddy Cole, all on one night and under one roof. When all is said and done, you still may not buy into the “real jazz” dogma. But then again, you don’t have to buy it to enjoy it. The Mid-Atlantic Jazz Festival runs Feb. 14 to 17 at the Hilton Washington D.C./Rockville Hotel, 1750 Rockville Pike, Rockville. $15–$205. (301) 563-9330. midatlanticjazzfestival.org.