love your themelesses, so many smart clues and entries! love SPARERIBS, FREEDRINK, SNOREFEST, and love the clues for PACT, SLAPS, NOCAP, TIMER, SHELF, LEFT, LOCO, and RAMEN--there were so many moments where i smiled while solving the puzzle. i do think the clue for EMO might work better if it was [Music genre found once in "a blue moon"] to emphasize the pun :P
6A and 4D irritated me, but only because I know I should have been more open minded when reading the clues. 19D as well I suppose, while also appreciating that it didn't require specific music knowledge. Learning 20A was also pretty great.