Danville is a quiet, upscale bedroom community where not much happens. That is, until you happen upon Randy and Stephanie Krul’s Two Left Feet, where the Friday night West Coast Swing party is known nationally to fans of California’s official state dance. Newbies gawk at the spectacle as elite dancers ranging from teens to the Medicare set spin across the crowded floor to tunes from Beyoncé, Justin, and Maroon 5. There are lessons, too; seven days a week, dance students descend on the biggest dance floor in Contra Costa County to learn everything from two-step to waltz. Hour-long classes are $13, with a post-class dance party on Friday and Saturday nights. Three rooms separate beginners from advanced students, and partners are not required. If you get shy, you can always linger in the back room, where dancers practice steps and yummy refreshments await. Stop in one night, and let your inner Benji Schwimmer loose; the So You Think You Can Dance champion got his start in West Coast Swing.