The label "progressive rock" didn't always connote the overwrought, empty virtuosity of Yes, Emerson, Lake and Palmer, or King Crimson. Long before gongs became a staple for rock drummers, German bands like Can, Neu, and Amon Dul were pushing the envelope in risky but usually interesting ways that relied on ideas rather than technical overkill. More than any of the bands the British music press derisively tagged as "Krautrock," Faust carried out their breathless musical experiments with staggering verve, energy, creativity, and success. Their dizzying pastiches melded pop, rock grooves, woolly free-jazz excursions, ethnic strains, and, perhaps most influentially, boldly applied noise--and when they disbanded in 1973 after only four years together, they left a vibrant legacy via a handful of albums. The Faust Tapes (ReR/Cuneiform), recorded between 1971 and 1973, brilliantly demonstrates their singular methodology, as 26 disparate passages ranging from catchy ditties to formless blurts are assembled into one seamless, flowing whole. Such wild ambition was their forte: a recently reissued recording, Outside the Dream Syndicate (Table of the Elements), for example, finds members of Faust backing violinist Tony Conrad (a disciple of La Monte Young) for 75 minutes of exhilarating microtonal drones. Faust have recently played a handful of European shows after 19 years of inactivity, and a couple of new recordings, some live, are forthcoming; but it'd be difficult to pre- dict what they'll sound like for this show, one of only five U.S. ap- pearances. Truly an event. Opening are New Zealand's Gate, a newer band led by former Dead C. guitarist Michael Morley, and Chicago's superb Gastr del Sol, who've just released a terrific debut album, Crookt, Crackt, or Fly (Drag City). Wednesday, 9 PM, Lounge Ax, 2438 N. Lincoln; 525-6620.