Depending on your viewpoint, Spectrum‘s Sonic Boom has written numerous songs over the past 10 years—or written the same song repeatedly. Mr. Boom, the former co-leader of Spacemen 3 and organizer of the ambient experimental group E.A.R., favors quiet oscillations that lead to hazy destinations. In his one-chord instrumental drones and his two-chord pop numbers, the sound effects that wash over the music are its most important element. While this technique may be simple, the results are usually intimate and beautiful. With the hyperclean pop of Air Miami and the noisy melodicism of the Ropers at 10:30 p.m. at the Black Cat, 1831 14th St. NW. $6. (202) 667-7960. (Chip Porter)