Tucked into a basement on a residential block in Harlem, the American Legion Post 398 pours booze from nips, not bottles, and Beyonce butts up to Bobby Womack in the jukebox. If this VFW post seems like an impossible secret, it’s not: organist Seleno Clarke's Sunday night jazz jam is legendary in the underground. The Hammond B3 maestro leads a top-notch, sometimes famous, R&B-style groove band that attracts local regulars and curious visitors alike. Still, the no-frills dive bar vibe suggests a bygone era and atmosphere tough to find anywhere else in Manhattan. Wednesday, Thursday, and Sunday are jazz nights, while Friday and Saturday are disco (and funk) nights. Order soul food staples like fried fish, collards, and rum cake off of hand-scrawled menus, and find the spacious back patio to air things out during the hot, summer months. Be polite and sign in when you walk through the door. The staff is welcoming and foster wholesome fun: good music, good food, and (especially on disco nights) plenty of dancing. There’s no cover but Post 398 is cash only and closes by midnight.