When The Forms first announced that their next release would be a remix EP called Derealization, I was cautiously optimistic. The Forms are great; remix albums typically are not. Still, their track record insisted they could pull it off. The group’s two albums—it’s difficult to call them “full-lengths” when Icarus runs 18 minutes and The Forms runs 30—and stray covers (Billy Joel’s “We Didn’t Start the Fire,” R.E.M.’s “Ignoreland”) are universally excellent. Beyond their intriguing, off-kilter guitar tones and ear-worm vocal hooks, The Forms’ greatest strength is their ability to revisit and revise the past. Icarus applies the editorial acumen of Wire’s Pink Flag to mid 1990s emo like Sunny Day Real Estate, fragmenting the song structures without losing sight of the emotional charge. The Forms, an album that gets better with every spin, envisions an alternate universe of 1990s indie/emo/math-rock where groups like Polvo could really sing, placing the vocals on top of the mix instead of burying them beneath the shifting guitar patterns. Changing the vocal intonation of and adding a droning, post-punk bass line to “We Didn’t Start the Fire” cleansed decades of its brain-numbing melody. With only an hour of widely available music to date, I was thrilled to hear anything new from the Forms, but opting for a remix EP—and a much delayed one at that—over their first album since 2007 seemed strange.

I’d hoped to pick up a physical copy of Derealization when I saw The Forms play a snow-sabotaged set at T.T. the Bear’s on December 28, only to learn that it wouldn’t be available until February. Nevertheless, I gained a much clearer idea of what “remix” means to the Forms.

I expected to see a four-piece rock band, but I’d missed the announcement that The Forms had been pared down to a two-piece. Alex Tween and Matt Walsh set up their keyboards/midi controllers first, with only Walsh having guitars in tow. They opened with an accordion and steel drum rendition of “Knowledge in Hand,” followed it with a synthesizer and miniature guitar reimagining of “Focus,” then turned “Red Gun” into electro-pop. I knew the melodies and the lyrics, but each had been pushed and pulled to fit their new arrangements, none of which sounded remotely like Sunny Day Real Estate or Polvo. Every song added some new element to the mix—’80s drum pads, dexterous guitar riffs, falsetto vocal runs—and by the end of the set, I got it. The band had been remixed. No wonder why Derealization took so long.

That’s the difference between Derealization and the hit-and-mostly-miss remix compilations I have from other rock bands (Mogwai, Swirlies, Dismemberment Plan, Bloc Party, Isis, Explosions in the Sky, Minus the Bear, etc.): The Forms are actively working with these versions. Remix albums are closed circuits. Groups send their material out to remixers, who rearrange it, add their own touches, and generally apply their own aesthetic to it. Once these remixes have been collected, the respective aesthetics rub against each other awkwardly. Some work, some don’t. But even in the case of a truly successful remix—Justin Broadrick’s take on Pelican’s “Angel Tears,” Kevin Shields’ explosion of “Mogwai Fear Satan”—it’s a static object upon release. Mogwai and Pelican haven’t performed those versions live. The very thought of that—“We’ve been learning how to play this remix of our song and rehearsing it a lot”—sounds comical. Remixes aren’t usually written or treated like original songs.

Then again, Derealization isn’t a traditional remix album. It may have started out as one, but Tween and Walsh did the rearrangements, not outside contractors. Collaborators color the songs, but don’t fully dictate the sound. Derealization is halfway between a remix album and a sharp directional turn, like Bob Mould’s embrace of electronic music on Modulate (except, you know, good). These songs are built on old material, but they stand on their own as new compositions. Guest vocalists The National’s Matt Berninger, Pattern Is Movement’s Andrew Thiboldeaux, and (especially) Shudder to Think’s Craig Wedren excel with The Forms’ material. Tween’s vocals in turn have improved to better fit the pop nature of the new versions. New instrumental choices like strings, acoustic guitar, electronic programming, synth bass, and drum machines never seem out of place. The switch from rock to pop as the dominant genre tag seems all too easy, especially on the Wedren-fronted highlight “Finally.” If only all “remix” albums went through this ringer.

And the remixing—in terms of the band perspective—isn’t over. After seeing The Forms again last night (opening for the Dismemberment Plan), I was amazed by how different the songs are in the live setting: much more electronic, much more dance-oriented. It’s a jarring flip from anyone solely familiar with The Forms’ past work, but Derealization acts as a buffer between the eras. It’s also encouraging that The Forms played at least three new songs, suggesting that a new release might not be four years away.

Derealization is getting a CDEP pressing, but I recommend the stark collision of past and present on the upcoming LP pressing of Derealization, which puts the remix EP on one side and Icarus on the flip. It makes logistical sense—Icarus hits vinyl for the first time—but it also showcases two vastly different eras of the band in the same place. Maybe someday the rock band incarnation of The Forms will open for the electro-pop version.

The only time I’d seen Shudder to Think or, more specifically, a member of Shudder to Think was at a Girls Against Boys show at the Mercury Lounge in early 1999. I saw Craig Wedren at the bar while on my way to the merch table and stopped for a second in a “Should I talk to you or leave you alone?” moment of panic. Being an awe-struck eighteen-year-old at the time of show, I opted for the latter option. I’ve occasionally regretted that decision, knowing that whatever I would’ve said—“Pony Express Record is one of my favorite records of all time! Could you make a sequel to it?”—would be an embarrassing admission from my inner fanboy, but other times I’m happy that I left Wedren in some higher rock star altitude.

The idea of a Shudder to Think reunion was never outrageous—Wedren and Larson are still touring musicians, the break-up wasn’t acrimonious, their best music isn’t dated—but my excitement was dependent upon the reunion’s focus. I admittedly lost some interest with 50,000 B.C., which I haven’t pulled out in years, and only dabbled in their soundtrack work. Their post-STT work is similarly disappointing—only a few songs from Wedren’s tepid Lapland and half of Larson’s Hot One debut have grabbed my attention. Clearly, their musical focus has changed since the epochal Pony Express Record, so which Shudder to Think would I get?

The opening band helped answer this question. I hadn’t previously heard Pattern Is Movement, but add them to this Spin article tracing the influence of Shudder to Think in modern and/or independent rock. (Deftones? I thought Chino pulled all of his effeminate vocal styles from Smiths records.) The Dead Science’s broken glam/goth-rock is the closest relative on that list to PIM’s marriage of operatic vocals, vintage organs, choir samples, and powerhouse drumming, but how exactly they seem influenced by STT differs. Whereas The Dead Science—the one time I saw them, at least—extracts Craig Wedren’s vocal register and some of their guitar dramatics, PIM pulls from the most outré moments on Pony Express Record, like the seemingly shapeless middle section of “Trackstar.” Even with busy, forceful drumming, the vocals floated above the arrangements in frequently incomprehensible operatic phrases. It’s hardly a surprise, then, that the genial members couldn’t quite induce a convincing sing-along on a cover of Radiohead’s “Everything in Its Right Place” or their own set closer. I respect the originality of Pattern Is Movement’s music (and their pro neck-beards), but like The Dead Science before them, it’s another instance of pulling the stranger elements from Shudder to Think and leaving the hooks behind.

Stealing a peak at Shudder to Think’s set list for the evening eased most of my fears—it would not be an evening of songs from High Art. Only one soundtrack song (“The Ballad of Maxwell Demon”) and two from 50,000 B.C. (“Call of the Playground” and “The Man Who Rolls,” which was cut), but six from Pony Express Record (“Hit Liquor,” “Gang of $,” “9 Fingers on You,” “Earthquakes Come Home,” “X-French Tee Shirt,” and “No Rm. 9, Kentucky”), four from Get Your Goat (“Love Catastrophe,” “Shake Your Halo Down,” “Pebbles,” and “She Wears He-Harem”), four from Funeral at the Movies (“Chocolate,” “Day Ditty,” “Lies about the Sky,” and “Red House”), and three from Ten Spot (“Rag,” “Jade-Dust Eyes,” and “About Three Dreams”). I typically don’t stress too much about set lists, but aside from wanting to hear the rest of Pony Express Record—I would’ve paid another $25 to hear “Chakka,” “Kissi Penny,” “Sweet Year Old,” and “Trackstar” as a second encore—their ability to recognize the best songs from their back catalog is impressive. I yelled for “Chakka,” but as I learned at the Juno reunion shows, if they didn’t rehearse a song, they’re almost certainly not going to play it, especially with new members in tow.

The Boston show marked the end of this “version” of the reunited Shudder to Think, with 50,000 B.C. drummer Kevin March giving way to Pony Express’s Adam Wade for their upcoming west Coast swing. Original bassist Stuart Hill opted out of the reunion, so Jesse Krakow was recruited as a replacement along with guitarist Mark Watrous. I understand the reticence involving bands reuniting with replacement members, but I’m happy with Wedren, Larson, and either March or Wade (although I would’ve preferred Wade, since he wrote the drum parts for Pony Express Record). While there were some telltale signs that this was, in fact, a reunion concert—Craig Wedren’s earpiece for the first half of their set, Wedren only playing guitar on every other song, Nathan Larson’s difficulties with his amp, the rhythm section getting a bit disjointed near the end of “X-French Tee Shirt,” those two guys onstage that I’d never seen before—Wedren’s stage presence and Larson’s guitar more than made up for any hiccups.

Whenever he wasn’t tethered to a guitar, Wedren hopped around the stage with surprising energy. He didn’t appear to have aged a day from the “X-French” video shoot. Larson, looking less like a glam-rock star and more like a communist insurgent, soldiered through those technical difficulties and sounded fantastic on the strafing lead guitar of “Gang of $.” Most of the stage banter was light, with Wedren trying to recall which girls inspired his earlier songs or joking that McCain was behind Larson’s amp difficulties. (Even with this approachable banter, I still left the club without haranguing Wedren with my decade-old anecdote. I’d rather maintain some of that awe, I suppose.) Wedren commented before “No Rm. 9, Kentucky” that the set felt very “punk rock,” an accurate statement that the dynamic “Kentucky” briefly refuted, but the low-key encore finished off the change, closing the night with the blissed-out “Day Ditty.”

The overall performance sat closer to the rejuvenated Polvo concert from this summer than the going-through-the-motions Pixies concert I attended back in 2004, but unlike Polvo, Shudder to Think didn’t revise their old songs or play new ones. They played their best songs and played them well, which was enough for the obsessive fans in the audience, but not enough for me to get my hopes up about a permanent reunion with new material (which Pattern Is Movement seemed to imply might happen, but Shudder to Think themselves did not mention).

It’s unfortunate, given the strength of the performance, that the Paradise didn’t look remotely full until Shudder to Think went on, and even then it did not appear to be a sellout. I could chalk some of this issue up to evening’s competition, since Les Savy Fav were playing over at the Middle East downstairs, the New Year was at the Middle East upstairs, the Feelies’ reunion show at the Roxy, and the Red Sox playoff game on television, but the truth might just be that Shudder to Think’s core fanbase hasn’t expanded like other reunited bands’ fanbases (Slint, Mission of Burma) have. Was this reunion too early? Did 50,000 B.C. turn off too many fans? Do Pony Express Record and their Dischord LPs not carry the proper cachet in today’s hipster enclaves? I overheard enough stories of people driving from nearby states or flying (from Scotland!) to know that the true devotees still care, but I’d hoped that more people had developed my awe of Shudder to Think since their initial demise. Even with that Spin article tracing their influence, I can’t think of any recent bands that have pulled off Shudder to Think’s blend of pop instincts and avant-garde tendencies in such an approachable package.