Quick: Count on one hand the number of bands that have released a seventh studio album that made more impact than a kernel of popcorn hitting the floor. Eventually, fresh creativity gives way to muscle memory. Nevertheless, Boise’s Built To Spill has earned the right to release a late-career record, even if the title might be a sneaky attempt to convince indie purists that 15 years of allegiance to Warner Bros. is A-OK.

Singer-guitarist-songwriter Doug Martsch has remained shockingly durable and consistent. That’s why early reviews of “Enemy” — treating it as somehow redemptive — are a bit mystifying. It’s not so much a return to form as a rich, layered textbook for diehard fans willing to savor and digest it repeatedly. Built To Spill’s prior album, 2006’s “You in Reverse,” roared with raw energy. At first casual listen, “Enemy” is sort of tedious. Give it time. It’s an epic, a grower, in the true sense of both words.

Guitar fans hoping for explosions in the sky will be let down. On “Oh Yeah,” the ax pyrotechnics are bombastic, but they feel less like psychedelic space-rock than a slow drift above a post-nuclear wasteland. Same with the 7-minute “Done.” It’s not a happy record. It’s more like an expansive, introspective synthesis of everything Built To Spill has done leading up to middle age, seasoned thoughtfully with inventive instrumentation and production flourishes. Newbies beware. But famished fanboys will sink their teeth into long-winded standouts such as “Tomorrow” and giggle knowingly at lines such as “When will these brain cells cut me some slack,” from the chiming, perky “Good Ol’ Boredom.”

Martsch’s lyrics are easier to relate to than in the past. It’s as if his own mortality — or that of his band — has dawned on him and caused him to stroke that beard as the smoke settles inside his dark backyard studio. What else inspires a melancholy, horn-laced ballad such as “Things Fall Apart”? “Stay out of my nightmares, stay out of my dreams,” he warns. “You’re not even welcome in my memories.” The entire album feels extra personal; “Pat” sounds like it could be about Pat Schmaljohn, a member of Martsch’s former band, Treepeople, who killed himself a decade ago.

The despair-tinged “Life’s a Dream” may be a lyrical cliche, but it’s easy to forgive. (As are the “la la la la” backing harmonies. Sort of. At least the voices don’t sing, “merrily, merrily, merrily.”) The point is well taken. Say what you will about Martsch’s heyday in the 1990s; this surprisingly artistic album’s proper place in the Built To Spill catalogue is nestled among the clouds.