For one thing, it’s the best climate-controlled jazz club in town. In either D.C.’s muggy summer or stinging winter, Twins offers a snug refuge from the elements. Indeed, the whole environment of the place is homey: well-lit, small enough that the tables feel intimate even though they’re crammed together. The minimum is low, the wait staff is friendly, and though the (mostly) Ethiopian food is uninspiring, they serve a great cheesecake. That atmosphere very much belies the edgy, often experimental music that tends to emanate from the bandstand. Twins presents jazz for jazz nerds: up-and-comers, obscurities, avant-garde adventurers, and local musicians with enough of a following to fill the seats. The type of musicians, in other words, who like to wander through the crowd between sets, shaking hands and chatting rather than disappearing into the dressing room.