What do you get when you gather a group of software developers, IT engineers, pathologists, artists, educators, service workers, and retirees to play music in a South Wedge home? Gregory Street Vagabonds, of course. Mostly consisting of amateur musicians, the Vagabonds' common denominator is a love of swing dancing. When they play The Little Theatre Café on Saturday, they'll time-travel back to the 1930s and '40s with big band classics and original tunes, written in a similar vein. Naturally, there will be a few holiday tunes mixed in. Featured performers will include vocalists Evan Miller and Gretta Cavatassi, and whoever's best at doing the Lindy Hop.