By the beginning of 1999, Doug Martsch had already accomplished incredible things. Built To Spill’s singer, songwriter, and guitarist was still just 29 years old, but as recapped in this Spin feature, his largely excellent discography included “three albums with Treepeople, his caterwauling first band formed during the brief period he lived in Seattle… three more with the Halo Benders, a pairing with Beat Happening frontman and K Records guru Calvin Johnson; and six with Built To Spill, including a rarities compilation and a Caustic Resin collaboration.” He’d also gotten Built To Spill signed to Warner Bros. during that post-Nirvana era when major labels were lapping up every promising underground band they could find. He’d used the money from that contract to move his girlfriend and son from a mobile home into a house in Boise with a recording studio out back and was about to pay off the house — all this without ascending to the heights of fame that made life so complicated for Nirvana and other alternative-era heroes.

Despite Martsch’s middle-class luxuries, that Spin profile — tied to the release of Keep It Like A Secret 20 years ago this Saturday — begins by explaining that he dressed and groomed himself in such low-budget fashion that he almost wasn’t allowed to enter the New Jersey Best Western where the band was staying because the staff thought he was a homeless loiterer. Reportedly, this was a not-infrequent occurrence. Author Eric Weisbard also mentions that Built To Spill were traveling without a roadie and routinely cramming all three touring members into a single hotel room, with one of them sleeping on a cot. When asked why he and his bandmates lived so simply despite living off a fat major-label contract, Martsch replied, “We know it’s not going to last. We know we’re not going to make it big.”

This was probably a smart decision. Built To Spill’s previous album, the astonishing Perfect From Now On, had sold only 43,000 copies in two years. The band was still playing events like one at Princeton called Bucks For Fucks, which Weisbard describes as “a university eating club party at which attendees dress as prostitutes or pimps.” Critics loved Built To Spill, they were making a living, and by the next album, 2001’s Ancient Melodies Of The Future, they’d even get a couple songs on the radio. But theirs was not the trajectory of lifelong rock stars.

Martsch may not have lived like a rock star, but he definitely played like one. Keep It Like A Secret is a document of Built To Spill’s glorious guitar-slinging peak — and arguably the best possible Goldilocks-approved middle ground between the pair of disparate classics that preceded it. With 1994’s There’s Nothing Wrong With Love, the band presented punchy guitar-pop songs with scrappy production and a distinctly twee disposition. With 1997’s Perfect From Now On, they pivoted to hi-fi space-prog epics that spurned conventional notions of length and structure. One sounded like a measly kid staring up at the sky, dwarfed by the unknowable vastness of the universe; the other sounded like God (defined by Marstch as “whoever you’re performing for”) staring down upon the same universe as it surged outward into infinity. With Keep It Like A Secret, Built To Spill and longtime producer Phil Ek maintained that larger-than-life scope while bringing back in the airtight pop songs. It fucking ruled.

The album hits hard from the very beginning, when “The Plan” comes careening in with a monsoon of riffs and strums. Singing Chomsky-inspired lyrics about the futility of enacting large-scale change, Martsch resembles a man lost at sea, fighting for his life amidst the crashing waves whipped up by his band. Except it’s a much brighter, poppier song than that description implies, with major-key riffs bombarding you from all directions and the rhythm section holding down a steady up-down undercurrent. Built To Spill say these songs were pieced together from the best parts of jam sessions, and you can hear it in the way “The Plan” progresses from those initial verses to its rocked-out instrumental midsection and on into a simple, gorgeous conclusion. There’s a lot going on. Yet they never sound like they’re jamming; all those moving parts are meticulously orchestrated for maximum impact.

The dynamism doesn’t stop there. “Center Of The Universe,” Keep It Like A Secret’s purest pop song, bounces along cheerfully as Martsch rails against both his own false projections and those from the television, a pair of delightful riffs trading off like relay runners passing a baton. Things really open up on “Carry The Zero,” a lament for a once-interesting friend who is now “occupied with what other persons are occupied with and vice versa,” soundtracked by wistful guitar figures raining down until the levee breaks. The hard-charging “Sidewalk” continues to condemn mindless acceptance of conventional wisdom; mutating groove “Bad Light” and cascading multi-part journey “Time Trap” explore the limitations of knowledge and life itself, respectively; deep existential conundrums are sediment in the shimmering current that is “Else.”

In sound and substance, these songs are a platonic ideal for a stridently indie band scaling up to the majors: always critiquing the status quo, self-aware enough to indict the messenger too, yet unashamed to make the delivery system sparkle with the best polish job money can buy. Martsch always punched above his weight as a vocalist, pushing his twee-Neil-Young mewl to its limits in service of arching choruses (“I wanna see movies of my dreams!”) or electrifying outbursts (“Most of the time it’s out of sight!”). His voice had never sounded stronger or more confident than it did here, slinging melodies at least as sticky as those guitar riffs. If Perfect From Now On had been a daring left turn, this was ambitious in a different way, like taking standard-definition indie-rock and bumping it up to HD. Built To Spill were able to amplify all their best qualities rather than obscuring them as often happens when bands attempt this kind of leap.

Never is that truer than in Keep It Like A Secret’s closing movement, a trio of anthems that more than earn their relatively lengthy runtimes. Working backwards from the end, there is “Broken Chairs,” one of the few minor-key songs on the album, which crawls and whistles well past eight minutes so methodically that you might not notice Martsch’s cries of “Well alright!” intensifying until he’s practically growling at you. I used to think it was an underwhelming finish to a classic album, but now I appreciate the way the boiling-frog effect parallels poet Uhuru Black’s lyrics about escaping “broken chairs your body conforms to,” those societal forces that can bend you out of shape before you realize what’s happened. That, and I’ve realized the thing just rips, an encroaching wave of not-so-gently weeping guitars conjured with assistance from Quasi’s Sam Coomes.

Before that is “Temporarily Blind,” maybe the most purely beautiful five minutes of music on the album. It’s a Rube Goldberg machine of interlocking rhythms and melodic flourishes, gliding forward with a scope and purpose that verges on symphonic. Martsch seems to be singing about the way a finite perspective causes humanity to keep repeating our mistakes — “Bet you can’t tell I’m temporarily blind,” he coos, before wondering, “Isn’t everyone?” — but I’m not going to pretend I understand what he’s getting at. (And anyhow, “It’d take all day to explain it.”) Actual meaning aside, the music itself speaks volumes about the potential for joy in this world. Just press play and bask in it sometime.

And then there’s the album’s climax, the towering acrobat routine that is “You Were Right.” Martsch had previously showed off his enthusiasm for classic rock, be it the Pink Floyd planetarium-scapes of Perfect From Now On or the bizarre David Bowie subplot on “Distopian Dream Girl.” Here he literally tore pages from rock’s history books and, in effect, wrote himself in right alongside his heroes. “You were wrong when you said ‘Everything’s gonna be alright!'” he chides Bob Marley in the song’s soaring chorus. The verses bring a parade of more pessimistic classic-rock declarations Martsch can endorse: “You were right when you said all that glitters isn’t gold/ You were right when you said all we are is dust in the wind/ You were right when you said we’re all just bricks in the wall/ And when you said manic depression’s a frustrated mess.” The Stones, Dylan, Seger, Mellencamp, and the Doors get a reading too, and then Martsch concludes by asking you to consider this stuff as more than musical wallpaper: “Do you ever think about it?”

Built To Spill never reached the heights of ubiquity enjoyed by any of the artists Martsch quoted on “You Were Right.” Contrary to Weisbard’s prediction in that Spin story, the band did manage to stay signed to Warner Bros. up until the present, but not because they were selling out arenas or kicking out jam after generation-defining jam. To these ears, Built To Spill were never this awesome again, and certainly they were never again as central to the indie zeitgeist. Still, despite the band’s humble stature in the rock-god pantheon, Keep It Like A Secret has hardly lived up to its name. Along with Built To Spill’s other masterpieces, it’s been eagerly passed down through generations as an essential entry in the indie-rock canon. On the modest scale Martsch prefers, it has become its own kind of classic rock.