I find myself caring less and less about specific labels nowadays, betraying the days when label catalogs were a primary source of recommendations. So many of the labels I closely followed in the 1990s—Touch & Go, Matador, DeSoto, Dischord, OhioGold, Mud—have closed up shop, slowed their release schedules to a crawl, or changed focus. Medications recently commented on how difficult of a time they were having booking a tour in support of their new Dischord LP Completely Removed (a wonderful album—buy it now). Amid specifics like trying to get opening slots without being tour-long openers, the lack of a booking agent, Dischord’s non-interventionist nature, and the baffling disconnect between Faraquet fans and Medications fans comes the starkest reality: even a prominent, respected label like Dischord carries less weight nowadays. I remember when groups like Durian and Bald Rapunzel fell through the cracks because they couldn’t get on Dischord. Now that frame of reference is almost negligible. (Exceptions apply, of course—it seems like label recognition now applies more to no-fi punk, noise, and psych-rock than straight indie rock.) In its place is an increased emphasis on first-hand marketing techniques like Facebook, MySpace, YouTube and the hopes that the music itself will become the recommendation, since file-sharing removed the difficulty of tracking down most albums.

The Mylene Sheath is a bit of a throwback to those old days. The only reason I bought this Giants LP was because they pressed it. As I mentioned for the review of Constants’ The Foundation, The Machine, The Ascension, they go balls-out on their packaging. Neither They, the Undeserving nor The Four Trees is as elaborate as the Constants set or Junius’s The Martyrdom of a Catastrophist (which I’ve ogled in Newbury Comics a few times), but each release scratches a similar collector’s itch: Giants get a limited pressing of white vinyl; Caspian gets a full-color gatefold and nice half-white, half-pilsner vinyl. I’m not a Mylene Sheath completist by any means, but beyond the consistently impressive packaging, I know to expect post-rock or something that appeals to people who like post-rock. That description may be too limited to squeeze in the dramatic Cure-like lurching of Junius (any good label has exceptions to their stylistic accords), but I’d wager that I’m not far off. After all, the Mylene Sheath isn’t a geographically limited label like Dischord or Mud. True to form, both Giants and Caspian are post-rock groups. I’ll even venture to say that they’re both a certain kind of post-rock band, so bear with me as I establish what exactly that means.

I tend to think of post-rock in two interconnected ways: tiers and phases. There are three tiers: the top is the ideals, the second is the trendsetters, and the third is the followers. There’s the strict definition of doing making music against rock conventions, exemplified by bands like Talk Talk and Bark Psychosis in the ideals tier. These groups are difficult to emulate since there’s no defined aesthetic or songwriting blueprint to appropriate. The second tier is comprised of groups like Slint, Tortoise, Mogwai, and Godspeed You Black Emperor that help define the various branches of the genre of post-rock—Slint’s the source of the math-rock trappings and dynamic arcs, Tortoise is the source of the jazzy inflections, structural tinkering, and lack of angst, Mogwai’s the source of melodically geared instrumentals, and Godspeed’s the source of the collage-based twenty-minute epics with strings. (Boy, do post-rock groups love adding strings and other alternate instrumentation.) Argue for Sigur Rós, Do Make Say Think, or Explosions in the Sky, but those four bands would be on my Mount Rushmore of modern post-rock. Third, there are the groups that exist immediately within this genre without expanding its boundaries. They’ll argue about it—see the Mercury Program’s steadfast insistence that they’re separate from this discussion—but you know a post-rock band when you hear one. There’s a wide range of quality within this third tier—plenty of derivative bands are also thoroughly enjoyable—but it’s by far the largest. Truly original ideas are hard to come by.

Next, from a chronological perspective, there have been four major phases of post-rock: the Slint phase, the Tortoise phase, the Godspeed phase, and the Explosions in the Sky phase. (Sorry Mogwai, you came at the tail end of the Slint phase, but at least your collective face was still carved into theoretical rock. I also emphasize major, since there have been plenty of secondary phases.) The Slint phase was the least distinct, since groups were also influenced by the second-generation post-hardcore leanings of Rodan and Drive Like Jehu (which thereby lends itself to the dudes-only math-rock), but the emphasis on time-signature changes, dynamic shifts, and harmonic chimes goes back primarily to Slint. This phase lasted until the mid 1990s, although Mogwai kept it alive later in the decade with “Like Herod.” The Tortoise phase was the least prevalent, since you need some actual chops to appropriate jazz moves. (It’s also the least interesting—even a presumably likeable band like Pele was bland as hell on record.) This phase didn’t last particularly long—I’d say 1998 to 2001 or so—since it was so goddamn boring. (Tortoise excluded until It's All Around You.) The Godspeed phase removed some of those barriers—if you played viola in your high school orchestra, you were in—and opened up the compositions’ length and removed the emphasis on structural integrity. Its height was from 2000 (with the release of Lift Your Skinny Fists) to 2004, when their influence began to wane (although Yndi Halda's 2007 "EP" Enjoy Eternal Bliss certainly owes GYBE royalties). Finally, the Explosions in the Sky phase is the most distinct. “But EITS sound an awful lot like Slint and Mogwai,” you say. That’s entire true, but because of EITS’s high profile from soundtrack appearances and touring, they’re the go-to reference point for so many recent post-rock bands, not Slint or Mogwai.

What Explosions in the Sky did was simplify the template: two guitars, bass, and drums equals emotional instrumental rock. They made it look easy. You can’t understate the importance of that point. Kids can pick up the usual instruments, not worry about picking a singer, and play with a single goal in mind—creating an emotional arc. Because that’s the end goal, audiences are quick to respond. Win-win. It’s hard not to get wrapped up in post-rock shows since they’re so dramatic, especially hard when you haven’t tired of the trick. Explosions in the Sky’s true gift to post-rock was figuring out how to reach people who hadn’t tired of the trick. Soundtrack appearances in Friday Night Lights (both the film and the superior TV series) certainly did that. Touring endlessly helped. This logic is not a knock against EITS as a group—they put out two memorable LPs, Those Who Tell the Truth Shall Die… and The Earth Is Not a Cold Dead Place, they’re a great live band—but their influence has watered down the genre.

All of this leads me to these two LPs I picked up. Both groups are in the third tier and in the Explosions in the Sky phase. The specifics may differ—Giants write shorter, more compact songs; Caspian utilizes heavier riffs and ambient lulls—but it’s hard not to think of Explosions in the Sky as the primary reference point, albeit not the sole influence. If you’re dedicated to the genre, this specific branch of the genre, then you should certainly check Caspian, at least. Labels like the Mylene Sheath allow me to dabble in the guitar-rock side of post-rock with consistent results. Yes, I’ve exhausted myself with the likes of Red Sparowes and God Is an Astronaut, choosing (like many others) to focus on the drone/ambient side with Stars of the Lid, Eluvium, and Tim Hecker or the electronic side with Fuck Buttons, Errors, and Port-Royal (which is facing its own level of exhaustion), but sometimes the simple pleasures are the most rewarding.

The main two reasons why I hadn’t previously picked up any of Caspian’s LPs is that they’re a much more exciting live band and I’ve routinely come away from their recorded material wanting more. I’ve seen them a handful of times around Boston, but the one I remember most clearly was a performance at P.A.’s Lounge in Somerville. Much like the Explosions in the Sky show I caught at Café Paradiso in Urbana, this Caspian performance benefited greatly from the small size of the venue. I felt like I was right on top of their enormous sound. When they turned on their flashing strobe lights during the crashing, start-stop riffs of The Four Trees’s “Brombie,” it was downright disorienting. Putting epic songs in a small room is a recipe for success. They’re good in a more cavernous space like the Middle East Downstairs, but the effect is diminished. Is it any surprise that recording this material further lessens the effect? How many albums can replicate that experience?

That isn’t to say The Four Trees doesn’t capture some level of this rush. Epics like “Moksha,” “Crawlspace,” “Brombie,” and “Asa” eat up huge chunks of the runtime with their dramatic arcs, punishing riffs, and bursts of triumph. “White Space” recalls Hum’s heaviness and Tim Lash’s racing leads. The combination of thunderous drums, slide guitar leads, and acoustic guitar treatments gives “Book Nine” both texture and power. Those six tracks over forty-one minutes should be the envy of most modern post-rock bands. They have moments of beauty, bursts of ferocity, lulls for recharging, and a deft sense of timing.

However, it’s an hour-long album, and The Four Trees would have benefitted from some pruning, pardon the pun. I could do without a few of the mellow soundscapes, like “The Dropsonde,” “Our Breathe in Winter,” and “The Dove,” especially since the last two are inexplicably sequenced next to each other. “Reprise” is essentially a hidden track with another blasting crescendo waiting at the ending, perhaps indicting the acoustic outro of “Asa” as insufficient for an album closer. Given that The Four Trees is Caspian’s debut LP after the compact You Are the Composer EP, perhaps pulling out all of the stops was the logical next move, but they’re simply more interesting as a bruising post-rock band than a gentle ambient outfit. Hopefully their third album (sophomore release Tertia smoothed out the edges for too much blurred strumming) plays more to their strengths, giving me more moments like “Brombie” in their excellent live sets.

Similar to Caspian’s The Four Trees, Giants’ They, the Undeserving is the group’s first full-length following a debut EP (specifically a 2006 self-titled, four-song demo). Unlike Caspian, Giants didn’t bite off more than they could chew. Undeserving avoids the editing problems of The Four Trees. These six songs span thirty-five minutes, locking together as one long piece with three barely perceptible movements (“Birth,” “Plague,” and “Rest,” calling to mind the tripartite nature of Constants’ The Foundation, The Machine, The Ascension). Once I put this record on the turntable, I know I’m going to listen to the whole thing.

The problem comes after the record’s over. Sure, the ten-minute-long closing track “Withered Life: Communal Rhythm” is impressive, developing its melodic themes from its introductory military-roll drumming to its intersection of swooping and floating guitar leads and finally to the album’s last crescendo. Past that song, however, there’s a lot of pleasant Explosions in the Sky post-rock that fails to make a lasting impression. “Steps in Static Progression” has a staccato guitar part more typical to the post-emo of the Jealous Sound than contemporary post-rock, so at least it’s doing something different. Too many of these songs don’t take chances, don’t step out from their apparent inspirations.

Giants have a follow-up LP, 2008’s Old Stories, which was recently pressed on vinyl by Cavity Records. Part of me is interested in hearing whether Giants spent as much time on the details of their songwriting for that one as they did on the outline for They, the Undeserving, but I’m in no rush. I’d rather be teased with greatness than appeased with competence.