VIDEO: BILL, "Steve Pepper"

Gage doesn’t so much sing songs as tear through them, his vocals occasionally sounding as if they’re coming from someone twice his size. As he sings “Big Foot,” a track off of the band’s second and most recent album, Bat Man, Gage bellows the title line over and over, all the while pacing back and forth like some caged beast, swaying to the ominous, industrial-ish score. You think for sure his voice is going to give out any moment, but it never does. It’s magnificent.

“I had a boss once who’d seen Chuck Berry, Buddy Holly, James Brown,” notes Gage’s older brother, John Gage, who plays guitar, among other things, for BILL (the band, he insists, is spelled in all capital letters). “So I was playing a tape of Bill, and he had just walked into the place where we worked, and he says, ‘Who is that — Muddy Waters?’ And I was, like, here is a guy who has seen James Brown, and he’s saying Bill sounds like this 40-year-old black man.”

Bill isn’t Muddy Waters, obviously, and he isn’t James Brown, either. But he is a rock-and-roll trailblazer in one respect: though he is an exuberant performer and a natural rock vocalist, Bill has Down syndrome.

A pretty good time
I’m sitting with most of the band in the TV room of BILL guitarist Greg Ansin’s spacious two-story South End apartment. Ansin, Bill and John, drummer Daren Follower, and bassist Gaylen Moore (John’s fiancée) have recently finished taking some publicity shots. Instruments are scattered throughout the apartment. The band (minus guitarist Eric Morin, who’s not around today) will be playing together after I leave. Bill seems very excited about this.

As for our conversation . . . it’s odd, even by rock-band-interview standards. John had warned me by e-mail that his brother isn’t “much for small talk and storytelling (outside of some of his songs).” John, on the other hand, loves to talk. Which is fine. Because nobody knows BILL better than John, who has collaborated with his brother on the project for more than 20 years.

According to John, the brothers — who, at 46 and 42, are no youngsters — each developed an interest in the arts in the late ’70s while growing up in Laconia, New Hampshire. “You’d go by Bill’s room and it would sound like there’s a couple of TV shows going on at the same time. He’s performing little skits and doing characters back and forth, and he’s got music playing.

“So there I was, this lonely teenager, without a circle of friends. I was like, ‘Wow that sounds like he’s having a pretty good time in there.’ ”

John would eventually move to Boston and play in rock bands, including, briefly in 1986, the Zinnias, with Magnetic Fields’ Stephin Merritt. Bill would sometimes visit from New Hampshire. In 1987, John had the idea of putting together a band fronted by Bill to play an open-mic night. The fledgling band went on without any song list. “It was like we were going to put a backdrop up and let Bill do his thing,” recalls John.

It was a few years later that BILL coalesced into something more serious. In 1991, the band released its first album, the free-form Beatles Chinese. Before long, BILL began to cut into John’s time — mostly because, in order for the group to get together, John would have to spend a few days ferrying his brother to and from Laconia. (Sure enough, that’s how Bill got to our interview. He still resides in New Hampshire, living in a shared home and working a custodial job through Lakes Region Community Services.)

It also stressed out his family. “It was a big production whenever we’d do something,” says John. Eventually, though, the Gages warmed to the idea of the band, John explains. “My mom in the beginning . . . didn’t see artistic merit or therapeutic [merit] in it, now they do see it. They see how happy it makes him and how happy it makes other people.”

In search of big foot
Ironically, Bill, who essentially cannot read or write, is also the group’s songwriter. In fact, the band was named after the one word he can write legibly, “making it simple for him to create the logo (and sign autographs),” notes John on the band’s MySpace page. Bill’s is an internal sort of songwriting — one that, John continues, “is always in flux.”