" Welcome to the first night of the best tour in the world! " gushed Piebald frontman Travis Shettel last Friday at Avalon, the kickoff of a Boston-rock trek that has his outfit sandwiched between fellow buzzbands Cave In and the Damn Personals. " This is such a great idea, we should have thought of it years ago, " said guitarist Aaron Stuart, who was outfitted in a camouflage T-shirt and bandanna headband. " Oh wait, we did. " Indeed, Cave In and Piebald toured together back in 1997, when both were just getting started. And on this night, six years later, both seemed poised for spectacular breakthroughs.

From the ecstatic impromptu sing-alongs that buoyed Piebald’s set, you wouldn’t know the band are living in LA these days: it sounded as if every friend they had in the world were in the audience. (During their nostalgia-inducing smartcore anthem " King of the Road, " the Alex of the lyrics who " took over for Alex Van Halen " was in the wings, wearing a Rush T-shirt.) Drawing mostly from ’99’s Venetian Blinds and last year’s We Are the Only Friends We Have (both Big Wheel), their set ran the gamut from lighter-waving acoustic ballads to cantilevered prog epics. Shettel, a cross between Rivers Cuomo and Stephen Malkmus with a dash of David Byrne thrown in for good measure, unveiled a pair of fantastic new songs that suggested they’re in the midst of a stylistic overhaul. One, featuring his most elastic piano-playing to date, landed somewhere between late-’60s Beatles and Elton John’s Goodbye Yellow Brick Road; the other skirted unironic ’70s arena rock with a Freddie Mercury twist.

If you sought refuge from the war, Cave In’s set was the wrong place to be. Under cover of darkness, they took the stage with a hail of spectral sci-fi battlefield noise — radio static, laser fire, warp alarms. Stephen Brodsky let loose a guttural scream and they launched into " Come into Your Own, " from last year’s Tides of Tomorrow EP, a transitional release (their last for Boston’s Hydrahead before moving to RCA) that seemed to allude to their nervousness about evolving from indie-level favorites into major-league monsters of rock. This set — tightly sculpted, stupendously loud, pulverizing and darkly elegant — laid waste to any doubts: they’re ready for the big time.

They hammered home that point early on with " Inspire, " the most ferocious song on their new RCA debut, Antenna, an evil, caterwauling Zeppelin-esque riff capped by a chorus that would do Pearl Jam proud. Near the end, when they went back to the heavy artillery, Brodsky showed a flair for the heroic. " Jupiter! " he shouted over his shoulder, lunging with his guitar in the air, the cry of a man who means to attack the heavens. And then they did, unleashing a torrent of shrieking ray-gun glissandos and bunker-busting bass frequencies.

On Antenna, the band abandon Jupiter’s protracted space-rock campaigns in favor of shorter, precision-guided pop songs, but at Avalon they moved effortlessly between the two. They brought the single " Anchor " to an on-a-dime stop — delicate pause, throat-clearing cough — before resuming hostilities. Midway through, they dragged out their atmospheric, cathedral-like set pieces, including the new album’s eight-minute " Sea Frost, " which featured both their fabled toy ray guns and Brodsky’s Sadé-on-a-Sunny-Day falsetto. The back-to-back " Joy Opposites " and " Youth Overrided " tested the boundaries of incandescent alterna-pop as intriguingly as Jupiter stretched the outer limits of metal. One can only hope they haven’t stretched too far: by the time the band encored with Jupiter’s savage metalcore opus " Big Riff, " the room had dwindled to half-capacity.