One of the key sonic architects of 1980s psych rock, Pete "Sonic Boom" Kember has been further refining his astral aural projections under the Spectrum brand for the last 20 years. His natural inclination toward minimalist drone and analog-synth tomfoolery à la the BBC Radiophonic Workshop interacts with a druggy rock motorvation to produce music that's alternately spacey and fiery, blissfully beautiful and ominously turbulent. Spectrum's best-known album is titled Forever Alien, which has become Kember's aesthetic mission statement. (Comet, 922 E Pike St, 322-9272. 9 pm, $10, 21+.)