In hyped-up urban clubs where hard rhythms and blinding strobe lights rule, techno music — at turns hard and fast, at turns soft and swirling — provides the feverish pulse. On the dazzling tip is England’s The Orb. With ethereal choruses, nature sounds, and ever-evolving slower rhythms, the Orb takes you on a machine-driven mushroom trip. The Aubrey Mixes: The Ultraworld Excursions features material from the group’s U.S. debut, Adventures Beyond the Ultraworld, remixed in various psychedelic club styles. A