There’s a reason that the brothers Marsalis don’t recognize postmodern, “outside” music as jazz. In their hometown of New Orleans, modern (i.e., bop-based) jazz is the outside. Yes, it thrives, but in the city where Preservation Hall and the second line still rule the roost, bop is a counterculture movement. And in New Orleans, the figurehead for that movement is Ellis Marsalis, the piano-playing patriarch of jazz’s most famous family. Marsalis is a master—literally, a National Endowment for the Arts Jazz Master—as thoroughly in command of his old eighty-eight as a general is of his army. But his mastery extends beyond the keyboard and into the fundamentals of the music; he’s been a teacher and mentor to players of all instruments from horns to vocals. He’ll play tonight as part of a quartet, with saxophonist Derek Douget, bassist Jason Stewart, and youngest son Jason Marsalis on the drums. The man possesses as extensive a knowledge of and feel for jazz as anyone alive; no wonder his kids see no reason to transcend that.

Ellis Marsalis performs at 7:30 p.m. at The Howard Theatre, 620 T St. NW. $26-$30. (202) 803-2899. thehowardtheatre.com.