Most of the young crowd sports modern threads, though there are a fair number of pinstripes, polka dots and cocked fedoras. Upstairs--yes, in Heaven--the Daddies have just wrapped an hour-long set with the impressively titled "Ding-Dong Daddy of the D-car Line." The lyrics were inspired by a 1950's newspaper article about a polygamous train conductor.

"On his route, he'd woo these elderly spinsters," details singer Steve Perry, perched excitedly on the edge of a couch backstage. "He'd eventually married sixteen of them. He was a serial-marryin' guy! He'd had too much love." Gaunt and subtly pompadoured, the crooner glumly adds, "And he was sent to Alcatraz for this."

With their fourth album, Zoot Suit Riot, selling a quarter of a million copies, the Daddies have become standard-bearers of the neoswing sound that first reached the airwaves last year with the Squirrel Nut Zippers' "Hell." Inspired by big-band jump-blues greats like Duke Ellington and Louis Prima, Riot swells with wanton horn arrangements, runaway-train percussion and velvet-voiced come-ons like, "I wanna give ya a little taste of heaven/And he only wants to hold your hand." The title track has been embraced by Top Forty radio, MTV and an audience who would have as much trouble translating the phrase "Hit that jive, Jack!" as their grandparents would using the verb to mosh.

Growing up in Binghamton, New York, Perry, 34, discovered "interesting syncopated music" early, via tap and jazz lessons--though, he adds, "I mostly remember dancing to 'Sugar Sugar' in a bunny outfit with a carrot around my neck." After dropping out of the University of Oregon, the ex-chemistry major taught himslef to play the guitar and formed a garage band, the Jazz Greats. "We were terrible," says Perry. "That was the joke."

Perry came up with a better one after his mom sent him the Smithsonian Collection of Jazz for his birthday. He became obsessed and formed the Daddies in 1989, at a time when grunge dominated the region. Cool kids used fuzz boxes; the Daddies had spit valves.

"Horns gave you the taint of being a frat band," says Perry, who found support in the ska scene, touring with groups like the Mighty Mighty Bosstones. The Daddies got rhythm long before Swingers and the Squirrel Nut Zippers, but Perry worries about being part of a fad, insisting, "We never wanted to go and make it 1943. I love roots music, but I don't feel comfortable selling the nation this fashion. It's part of our mission not to milk this pose." Skeptics might disagree, pointing to the group's natty stage attire and its Forties-time-warp video for "Zoot Suit Riot." But onstage at the Masquerade, the band attempts to put the buggin' back into jitterbuggin', tossing ska and punk numbers into the mix, and this summer the Daddies will join the Warped Tour alongside Rancid and Bad Religion.

"There's no inherent reason why swing can't be a viable modern music," argues Perry. "Why is guitar rock more valid? Swing is better music, to my mind. Does it have to be all angst? When Count Basie got out there and smiled and plinked and plunked and the band was brassy, and it felt like a warm day and everything was going to be alright, what the hell's wrong with that? Maybe it isn't the end of the world." He breaks into a broad grin.

"And if it is, who the fuck cares?"