Did progressive rock get a bad rap from the post-punk generation? Lately, everyone from instrumental outfits such as Tortoise to four-track whiz kids such as Olivia Tremor Control has been reinvestigating the world of the epic song suite and the mind-twisting tempo change – with a vigor that suggests that maybe Rick Wakeman was right all along.

Or maybe half-right. Unlike their musical forefathers, the new exponents of prog aren't so much trying to retool Bach or revive the legend of King Arthur as they are scavenging for inspiration over a wider range of source material. For their part, Built to Spill dip into the psychedelic garden cultivated by guitar-based precursors, from the Beatles to the Flaming Lips.

Built to Spill are less a formal band than a shifting cast of musicians directed by songwriter, singer and multi-instrumentalist Doug Martsch of Boise, Idaho. Perfect From Now On, the outfit's third album, is eight tracks that check in at a total of more than 54 minutes, allowing Martsch room for his expansive melodies to shift course, fade and reappear, or to transform themselves into new tunes at different tempos. He layers on keyboards, percussion and cello – but not at the expense of the guitar-bass-drums foundation – and maintains an emphasis on instrumental passages that are short on flash but long on atmospheric swirl.

The longest works, particularly the nearly nine-minute "Untrustable/Pt. 2 (About Someone Else)," play like a series of seamlessly linked songs within a song, a journey that keeps spiraling higher before tumbling into a warehouse full of clocks and wind chimes. It's as if Martsch is elaborating on the lyrics in "I Would Hurt a Fly": "I can't get that sound you make out of my head/I can't even figure out what's making it."

But for all of Martsch's alluring arranging and songwriting, the personal cosmos glimpsed in lyrics like these, from "Randy Described Eternity," is a reminder of an earlier generation's excesses: "Every thousand years this metal sphere, 10 times the size of Jupiter/Floats just a few yards past the Earth/You climb on your roof/And take a swipe at it/With a single feather." Somewhere the prog dinosaurs are muttering, "He's one of us." (RS 753)

GREG KOT