While most people out on 16th Street on a Friday night are hitting the bars, one group opts for hippies over hipsters. Deepening into their chair poses, the practitioners at the Laughing Lotus Center are supported by an array of candles and live musicians, who accompany the transitions (or flow) between poses with a quiet sitar, a cello's rich hum, or the guttural drones of the didgeridoo. The result is music as therapy — or at least trance-like, blissed-out yoga. At the end of a session — which runs from 10 p.m. to midnight on Fridays — you can indulge in hot tea and ginger cookies, and then wonder, as you make your way back through the streets, how many of the people hailing cabs are actually reaching for the stars in warrior poses. Some nights really are best spent taking trips to the astral lands inside your mind, with live music, a floor mat, and a candle to show you the way.