The Big Roar,

the debut full-length CD from The Joy Formidable, lives up to its title (and the band's name) with a loud, cathartic mix of shoe-gazing anthems, grungy guitar squalls, and passionate vocals.

Even before their full-length debut arrived in January, the Welsh trio were getting buzz on the strength of several singles, a mini-album and, especially, live performances. They have toured relentlessly this year, playing opening gigs in arenas (they were at the Wells Fargo Center with the Foo Fighters a few weeks ago; they opened for Sir Paul McCartney in London a year ago), festivals (slated for this fall's Popped! Festival but had to cancel), and headlining gigs in small clubs, including a Toys for Tots benefit Monday at the North Star Bar.

Their sound is huge and seems built for the large stage, but singer-guitarist Ritzy Bryan relishes the club shows as much as the arena ones.

"The live side is a big, big part of this band," she says by phone from Jacksonville, Fla., where she and bassist Rhydian Dafydd and drummer Matt Thomas had just finished an afternoon slot at a festival. "It's important to play every gig with the same intent whether or not you're on the large stage or in the intimacy of a smaller venue, those sweaty basement clubs where you can put on a proper rock-and-roll show. I think the main thing is you get up there every night and you play like it's your last gig ever, you know? It doesn't matter how many people are in the audience."

Bryan creates a My Bloody Valentine-like wall of sound with myriad pedal effects on her guitar - witness the epic "Whirring," the song which caught the ear of the Foo Fighters' Dave Grohl when he heard it on the radio, prompting him to invite the band on tour.

Live, the musicians push the songs into the red, and they often end up pushing over the equipment on stage.

What's important to Bryan is that the emotions remain genuine, and she looks to Grohl and McCartney as inspirations for that.

"I'd hate for something to become so rehearsed and repetitive that you don't feel challenged in that sense. That's a massive thing if you can be like McCartney and the Foos and you've been playing these tracks for 20 years or more, and it's still that exciting," she says. "That's very much the way that we feel. Nothing ever becomes a job; you're not going through the motions. That's what you always want from a band: You want to escape into that intimacy, into something that feels truthful."

The Joy Formidable are barely four years old and only recently began work on their second album, holed up in a studio in rural Maine. But Bryan's in it for the long haul.

Can she imagine playing songs from The Big Roar 20 years from now?

"Yeah, absolutely. We've always viewed this as just the beginning, and there's a lot still to come."

It's a formidable beginning, indeed.

The Joy Formidable, a benefit for Toys for Tots with special guests, will play at 7 p.m. Monday at the North Star Bar, 2639 Poplar St. Tickets are available for new, unwrapped toys donated to Toys for Tots from 10 p.m. to midnight Friday at the Grape Room, 105 Grape St., Manayunk. Information: 215-787-0488, www.northstarbar.com.