Classic hip-hop, with its no-frills rhythms and shell-toe Adidas, seems anachronistic in an age ruled by shiny grills, stripper poles, and pimp cups overflowing with tangy, life-giving crunk juice. But vintage beats and rhymes never sound dated when they're delivered with the polish and poise of People Under the Stairs. Like fellow Cali crew Jurassic 5, MCs Double K and Thes One are hyped-up and positive, laying down metronome-steady flows over bright, soulful rhythms. Their study of music theory adds a progressive edge to the beats on Stepfather (2006) and the Tuxedo Rap series of remixes that followed — old-school indeed. Tonight you can help them celebrate ten years since the release of their first album, The Next Step.