Maybe it’s always been this way, but it seems the latest trends in indie bands are to either go really big or pare everything down. Examples: The two-person, girl-boy pop duo has exploded, not to mention the two person blues combo. Power trios seem on the rise — run-of-the-mill rhythm guitarists need not apply. On the other side of the spectrum, The Arcade Fire gains a member every time they tour, collectives like Broken Social Scene serve as loose conglomerations of lots of talented musicians, and even Wilco has bloated to six full-time members.

Of course, even if Architecture in Helsinki added an entire elementary school orchestra to their touring lineup, you get the sense Tim DeLaughter would find a way to ensure his group, The Polyphonic Spree, keeps its status as the biggest, most exuberant band in the land. And after DeLaughter and the Spree played to an enthusiastic crowd Saturday night at the 9:30 Club, it’s hard to see a pretender to the crown.

The band’s just released their third album, The Fragile Army, and — as I’m sure you’ve heard — ditched the white robes for black jumpsuits, complete with a small red cross on the side. The song topics got a little darker too, jumping from smiling at the sunrise each morning to George W. bashing, but it’s still big picture stuff, and DeLaughter’s still shouting it quite loudly and proudly.

But truth be told, you don’t so much notice those differences. Instead you focus on the much bigger light show than they've had in previous tours: more smoke, more glitter confetti explosions. And the performances themselves aren’t lacking in exuberance. “Younger Yesterday” featured an exalted chorus (then again, didn’t they all?), ringing out, “Now we know we’re beautiful,” before giving way to the double drummers bashing out a heavy backbeat coda. “Hold Me Now” — from their second release, Together We’re Heavy — blasted with bright, big band horns straight out of “All You Need is Love,” while DeLaughter pranced and exhorted.

The Fragile Army’s title track got dedicated to the President, and opened with a piano part nicked from “Karma Police” before morphing into something like Willy Wonka doing the national anthem. The set proper closed with another new song, “The Championship,” that captured the band at its best. Big synth swoons led into a double backbeat and then into the soaring choruses. More straightforward rock than most of their stuff, at its peak band members began to drop out, one-by-one, eventually leaving just drums, harp, and chorus, then only DeLaughter and a simple harp, leading the audience in singing, “All in good time/ Raise our voices.”

The band technically went to encore, but the room was buzzing and humming during the entire break, lights still flashing across the backdrop. A few minutes passed before the band emerged, dressed in their familiar white robes and led in a processional through the middle of the crowd and up onto the stage. The group thrives on this kind of drama, and the encore was positively euphoric. Two songs in, a twinkling piano introduced a cover of Nirvana’s “Lithium.” It got everyone bouncing up and down like it was 1991, but it wasn’t just an ironic, by-the-numbers thing. It genuinely seemed to fit with the Spree’s whole aesthetic, and even featured more of those bright horns on the chorus. They closed with a couple more, but at this point the audience was eating out of their hand. It was terrific rock theater, with big smiles all around.