Indie K-pop outfit 9 and the Numbers dig up musical comforts from decades past and knit them into a blanket of cozy tunes for the here and now. The quartet formed in 2009, drawing from a variety of broken-in genres ranging from ‘50s doo-wop to ‘60s British rock. They operate best at midtempo, bringing in country-style guitar arrangements (“Tear Wind”) and folksy plucking (“Hider and Seeker”). But 9 and the Numbers can also dial up something faster, and they're fond of fizzy synth-pop (“Goodbye Dance”) as a complement to the more retro stuff they do so well.