"Polarity" is all knotty tension and anticipatory gestures, making it an appropriate opening cut for Stellar Om Source’s new album on RVNG, Joy One Mile. Christelle Gualdi’s project takes a key moment in dance music history as its central building block, essentially looking to the point where bubbly acid rhythms morphed into the inward looking work of the early Warp stable. It’s not until the midway mark that Gualdi eases up on some of the pressure, sending a chilly synth pattern across its prickly spine, settling into a steady rhythm, and positioning “Polarity” in a place of muted exuberance.