IT'S AMAZING how quickly we become accustomed to new technology. Twenty years ago, synthesizers were unheard of in popular music; 15 years later, the idea of building a band around a bank of synthesizers had evolved into an actual sub-genre. These days, synthesizers are so common that bands are known to boast about not using them.

All of which makes it fascinating to wade through Tangerine Dream's ". . . In the Beginning," a six-record anthology of the group's earliest recordings. Tangerine Dream was a pioneer in rock electronics, virtually inventing the synth-rock vocabulary; in fact, "Electronic Meditation," its recording debut, didn't use synthesizers at all, relying instead on a battery of sounds borrowed from composer Karlheinz Stockhausen.

As the band added synthesizers to its lineup, its sound changed, often radically. "Alpha Centauri," for example, floated between hard rock and free jazz with blustery exuberance, while the four sides of "Zeit" occasionally grew so quiet as to verge on the inaudible. Perhaps the greatest revelation in the set is "Green Desert," a hitherto unreleased album that presages the sort of cosmic rock sound that catapulted the group to fame in the mid-'70s.

For all that, though, those recordings sound almost quaint when compared to the band's current work. The music the band produced for the film "Legend," for example, is so delicately crafted that the electronics sometimes go virtually unnoticed. Part of it is the band's command of contemporary technology, but the real secret to the soundtrack's success is Tangerine Dream's ability to evoke definable moods without succumbing to cliche.

Still, the band shows its greatest strengths when working on its own, as on its new studio album "Underwater Sunlight." Not only does the music boast a surprising pop sensibility, leaning less on atmospherics than actual melody, but it finds Tangerine Dream conjuring a perfect universe of sound, making the which-instrument-played-what question utterly irrelevant.

TANGERINE DREAM -- " . . . In the Beginning" (Relativity EMC 8066); "Music from the Motion Picture Soundtrack 'Legend' " (MCA-6165); "Underwater Sunlight" (Relatively EMC 8113). Appearing Sunday at the Warner Theater.