When my roommate said he had never heard of Andrew Bird, I tried to describe him: “He’s that guy who whistles…” —And that’s pretty much as far as I could get. His signature whistling is one of the few quantifiable characteristics of Bird’s flighty, unique brand of music-making. The rest is an unpredictable smattering of sounds that meander along gracefully, occasionally straying a bit from reality to go down some sidestreet of Bird’s convoluted psyche. To get it, you really have to see it.

I first saw Bird at the Merriweather Post Pavilion in Washington last spring when he opened for the Decemberists. He was captivating then, even though I was sprawled on a lawn hundreds of feet away from the stage. But Saturday night, USC’s Bovard auditorium was a far more intimate setting to take in the uber-cozy Bird experience.

The drawback to the Bovard is that it’s slightly better suited to concertos than to rock concerts. Its flip-up cushy seats and austere insides make you feel like you should hush up and listen to the assistant dean’s speech, or the like. It was a little weird being at a concert surrounded by 18-year-olds who sat quietly in their seats, clapping politely with not so much as a head-bop or a hand-sway. But, then again, Andrew Bird isn’t really rock. He’s part orchestra, part philosopher, and oh, yeah…part whistler.

Let’s talk about the whistling. It’s real. It comes from his mouth, not some synthesizer. And it’s perfectly on-pitch as it bursts in at exactly the right time in the cheerier-sounding tunes from 2009′s Noble Beast. —But that’s not all there is to him. Though he occasionally plays with a full band, on Saturday Bird had a plethora of instruments strapped to him, chimney-sweep-from-Mary-Poppins style, and he strummed and switched them around to perform all his songs as a one-man indie band. A guitar hung from his back as he plucked the violin. There was a keyboard to his left and his ubiquitous double-ended spinning horn behind him. At one point, he removed one shoe to reveal a hot pink sock, the better to peck at his foot pedals with.

As he played some of the all-instrumental tracks from Useless Creatures, he seemed to be having a religious experience, losing himself in the violin. Then he explained that it’s just the sort of thing that happens when he cloisters himself to write music in his Western Illinois barn, which is a fittingly folksy image for his sound.

Bird’s interjections and personal stories are one of the best aspects of seeing him live. Partly because some of his work is so dense that it helps to have a little background on the heavy thinking behind it. For example, “Effigy,” Bird said, used to be the same song as “Oh No,” but then he split them up because it got to be “too full of ideas.” And the song “Imitosis,” as it turns out, was originally called “Capital I,” and stemmed from an idea Bird had about a scientist studying “the reason why kids are so mean.” Then there’s “Natural Disaster,” which mentions pleurisy, a Victorian lung disease he contracted once from frequenting too many smoky bars in Chicago. Luckily, it didn’t seem to damage his singing voice any.

Halfway through the show, Bird announced that now that he’s returned from Japan, he plans to “hang his hat” in Los Angeles for a while. I’m excited to see whether our fair city will inspire him with celebrities or smog, giving rise to more songs that take a while to chew on but ultimately go down easy. Hopefully we don’t give him any diseases to write about.

—Olga Khazan