Indie rock was born to be an alternative to the testosterone fueled world of high school football. While the jocks were out swilling cheap beer and groping cheerleaders, the future stars of indie rock were home noodling on their instruments, obsessing over their record collections, or posting to their e-journals. And while none of the members of Explosions in the Sky – the Texas post-rock band playing three nights at Bowery Ballroom this week – look like they could do much damage to a tackling dummy, you might say they owe their success to high school football. The group’s big break came when they were chosen to score Peter Berg’s 2004 film “Friday Night Lights” about big-time Texas high school football.

My first reaction to the film – as it must have been many others (even jocks) – was to look up the band. Their liquid guitar instrumentals made the frenzy of two-a-days more frenzied, and the pregnant pause just before the ball is snapped more expectant. It was even better suited to the non-floodlit moments – shots of an empty locker room lined with equipment, dawn rising over a vacant stadium. Like Miles Davis’s fusion jazz in Gus Van Sant’s “Finding Forrester” (an underappreciated symbiosis of sound and image), it invested the quiet moments with a gossamer beauty that never let the tension slack.

Slow-evolving and swelling, Explosions’s music is equally cinematic on its own. As the titles suggest – “The Sky Above, the Field Below,” “Snow and Lights,” “Glittering Blackness” – the songs project their own images onto the mind’s big screen. Comparisons to more established post-rockers – especially Godspeed You Black Emperor and Mogwai – are inevitable, but Explosions holds its own in this company, and even manages to carve its own niche. Less bleakly apocalyptic than Godspeed (but who isn’t?) and less moody than Mogwai, Explosions can be as epic as either and prettier than both, giving access to a broader emotional range.

The effectiveness of the songs owes as much to the band’s patience as its proficiency. Themes and phrases are often developed for six or eight minutes before they really begin to rock. It’s to the band’s credit that they don’t pander or overindulge us, but their listeners have to learn the same patience. The highs become a drug, and it’s tempting to try to cut corners to reach them. As I re-listened to the albums, I found myself dragging the progress cursor through the plodding middle sections to get to the good stuff – only to discover that it wasn’t there. The music is tamper-proofed: All the power is in the contrast, and it’s only after you’ve been lulled that you can be amazed.

Explosions in the Sky has answered its newfound notoriety not with a new album, but with the re-release of an old one and a mail-order-only EP. “How Strange, Innocence,” widely released this October by their label Temporary Residence, was originally put out as a few hundred CD-R burns in 2000. It shows a young band with a steady command of dynamics and a somewhat mimetic ear. “A Song For Our Fathers,” which opens the album, is a conversation between fluid bass, calligraphic plucked notes, and reverb animal moans. “Snow and Lights” inverts the typical soft-loud formula, starting with flurried white noise, then entering a long, slow thaw. “Look Into the Air” has the bouncy chords and bent-note ellipses of a Built To Spill song.

Explosions’s other new release is the latest installment of Temporary Residence’s subscription mail-order series, “Travels in Constants.” “The Rescue” consists of eight songs, recorded over eight days, helpfully titled “Day One” through “Day Eight.” It finds the band stretching out and experimenting, and there are two big changes to note. First, the songs are short – two to five minutes, instead of the usual eight to ten. Second, while still built around multiple guitars, they incorporate other instruments and even – gasp! – voices.

It’s a pretty album – light and casual – but lacks the wide-screen grandeur of their other releases. “Day Two” features piano and airy vocals reminiscent of Death in Vegas’s contribution to the “Lost in Translation” soundtrack. “Day Five” starts as a cheery Galaxie 500 song, but ends up closer to the twinkling pastorals of Mum. “Day Three” is a hodgepodge of spoken samples and crystal-shard guitars not unlike sections of Godspeed’s debut “F#A# (Infinity)” (without the cracked, oracular raving).

It will be interesting to see what they do with it in their famously intense live show. No doubt the highs will still belong to the guitars, but more musical variety in the developmental sections could give us more to hear while we wait for the fireworks.

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Brooklyn’s Grizzly Bear played to a full and fashionably hirsute crowd (including members of the Yeah Yeah Yeahs,TV on the Radio, and Calla) Friday at Tonic.The band is enjoying some success among the PitchforkMedia crowd as a psych-folk outfit, vaguely in keeping with the outre spirit of Animal Collective and Syd Barrett. But such comparisons do the compared – not to mention the listener – a disservice.

The show had all the trappings of psych-folk.The band played before a 6-foot-long crocheted folk-art backdrop that spelled “Friend” in quotation marks. Singer-songwriter Edward Droste and a bandmate sitting indianstyle on the floor took turns playing an autoharp. But the music failed to rise to even the modest expectations of the genre (or any). There were no real songs, merely the suggestion of them. And sooner or later, everything reverted to a primordial ooze of tranquilized bass, chant-like delivery, sunken keyboards, and formless Velvet Underground drone. The only mystery of it was how so many LES scenesters and RISD grads could take it so seriously.

Explosions in the Sky plays the Bowery Ballroom on Monday and Wednesday night (6 Delancey Street at Bowery, 212-533-2111).