Its old location, across the street from where it is today, hosted the likes of Charlie Parker and Billie Holiday. The present-day stage has seen Branford Marsalis and Chick Corea. For all that, it’s still a neighborhood joint. Wally’s offers live jazz every night of the year, no cover, and some of the cheapest drinks in the city. But there’s something else about it—the history, the perpetual smokiness, the cramped stage, and narrow bar—that makes it Boston’s jazz scene. Jazz was meant to be heard at Wally’s, where customers get on stage and jam with the band and the musicians don’t need to be pretty.