If knowing exactly who your friends are is a blessing, then Cave In fans could use a little divine intervention. Rewind a mere five years and the young quintet-going-on-quartet from Boston had released two easy-to-peg full-lengths, Beyond Hypothermia and Until Your Heart Stops. Back then, Cave In crafted a particularly mean brand of boogie, full of deathly growls, down-tuned chug, and sprinting kick drums. If the music sometimes seemed a tad generic, the contrapuntal percussiveness of tracks such as Heart standouts “Juggernaut” and “Terminal Deity” also reaffirmed the possibilities of Beantown brutalism. Like fellow Bostonians Converge and Isis, the band was out to spread the metal love, but it also excelled at dovetailing belligerent, punk-rooted melodies and rhythms, and it even threw in a little syrupy psych for the heads.

As far as reinvention goes, though, 2000’s Jupiter could’ve given David Bowie whiplash. By that time, Cave In had plugged in to OK Computer and decided to chuck the metal into the Mystic. Or at least most of it: “Big Riff” found singer-guitarist Stephen Brodsky crooning in a sweet falsetto and dredging up pure vocal sewage in the same line (“You’re another coat of red in hell”) on top of a rhythm section that sounded like road cones bouncing over an Econoline roof. But that track was the extreme-metal exception that proved the Britpop rule: Fast-forward anywhere on Jupiter and you’re more likely to hear chiming, delay-soaked guitars and Brodsky’s best Thom Yorke than straining Marshalls and gravel-toned orc vox. Apropos of its title, Jupiter was more 2001 than The Decline of Western Civilization 2.

Of course, many fans of the abrasive old-style Cave In screamed Judas. But they were wrong: Cave In hadn’t given up on its sound so much as re-envisioned it. The old intensity was still there, and when guitarist Adam McGrath ran off with an uncluttered single-digit melody line and Brodsky’s voice gave chase on a track such as “In the Stream of Commerce,” the band didn’t really sound like Radiohead or even Sabbath. It sounded like something we hadn’t heard before—something in-between; something liminal. Jupiter’s succession of big, weird, magnetic hooks took a while to get your head around, but they all pointed toward a place where any open-minded musical extremist would feel more or less at home.

Yet what then seemed to be a fantastic art-rock aesthetic turned out a stepping stone to a much less interesting world. Antenna, Cave In’s fourth full-length and its first for a major, is another jarring change, even if the distance from the prog-pop of Jupiter to this record isn’t as great as the expanse that came before. And it’s not just that Brodsky & Co. have further smoothed away the rough edges—this time, the shock comes from hearing Cave In wholeheartedly pursue commercial airplay. In an Amazon.com review of Heart, “fhqwhgads” from Boston frets that “carson daily” will call Antenna “cave in’s debut.” And the poor guy’s probably right: Massive, history-erasing face-time on TRL seems ridiculous only until you’ve heard the thing. Indeed, first single “Anchor” is an overcompressed bullet aimed straight at the heart of the alt-rock marketplace.

That track is just about as anonymous as post-Nirvana Heatseekers can get, and it’s easy to imagine some suit at RCA picking it from Antenna at random. That’s because most of the album could be slapped in rotation between Foo Fighters and Zwan and fade easily into the fabric of contemporary teenagerdom. Antenna is perfect in all the wrong ways: From the three-chord pop-punk of “Penny Racer” to the acoustic power balladry of “Beautiful Son,” the disc often sounds commissioned by a marketing committee. And whereas even Jupiter maintained a live-in-the-studio rawness, Rich Costey (who’s worked with Audioslave, Sum 41, and, uh, Hoobastank) produced this one into supercompetent mush.

The few songs that stand out from what the band’s Web site calls the disc’s “more linear and unashamed rock” also happen to be survivors from the earliest rounds of post-Jupiter demos. Buried in the middle of the track list, the nine-minute, fuzz-bass-burned “Seafrost” is the only thing here that recalls the expansive song lengths of yore. Wrapped with shoegazerish guitar drone and pushed forward by stop-start tribal drumming, the song is one of only two here that feature Brodsky’s haunting falsetto (“I’m free-ah-zing”), which has disappeared altogether from Cave In’s most recent compositions.

Brodsky’s signature vocal stylings also pop up on the following track, “Rubber and Glue,” which was apparently called “Bigger Riff” until the band realized it isn’t. That said, the song is at least a “Big Riff v2.0″—and it’s as good as anything from Cave In’s glory days. The string-bending two-note motif in question is simple by Heart standards, but amid Antenna’s modern-rock blandness, it’s pure metal manna. And when the band hits the chorus, Brodsky’s voice and McGrath’s six-string do the dance once more, twisting and winding in sync through the central melody. “If I could make all of my words come/I’d ditch numbers altogether for sure,” Brodsky sings as McGrath scales up and down his fretboard, merging mere words and strings into a blissed-out unity of sound.

Perhaps we’ll never know if Cave In jumped or was pushed away from such singular hooks. But one thing is clear: It was a mistake. The MTV rock of cuts such as “Inspire” and “Joy Opposites” makes for half-decent popular music, but certainly not good art music. Somewhere along the line, someone assumed the worst of the band’s fanbase. As a result, Antenna is just too dumbed-down for its own good. Brodsky and his bandmates now play for some maybe-demographic, not as if their lives depended on it. Too bad: They used to be grand. CP