Dropkick Murphys celebrate with party in Paradise

The Dropkick Murphys turned in a spirited, fast-paced performance at the Paradise on the eve of St. Patrick's Day. (ARAM BOGHOSIAN FOR THE BOSTON GLOBE)

"How'd you guys get tickets to the show?" bassist Ken Casey deadpanned on Sunday, squinting into a rack of Kelly green stage lights. "I couldn't even get tickets." Part statement of fact; mostly joke.

By the time the Dropkick Murphys marched across the darkened stage at the Paradise Rock Club at 9:30 p.m., the Boston band had already knocked off a long string of St. Patrick's Day weekend dates, including a gig at the IBEW Hall in Dorchester, and two at the Tsongas Arena in Lowell. All were sold out. (For those with the cash to spare, extra tickets to Sunday's show were going for more than $100 apiece on the Web.)

At the Paradise, a well-lubricated crowd spilled down from the club's top-level alcoves, across the pit, and out into a bottle-necked traffic jam at the narrow entryway. The floor was rough with energy: a few dozen Celtics jerseys, a few hundred upraised fists, a few thousand beads of sweat, and the occasional wayward fan - his hands wind-milling through the wet air - escorted by a phalanx of bouncers back out the door and onto Comm. Ave.

"You may be the only ones left standing in this town," said Casey, although it was unclear whether the crowd was standing or packed so tightly it was impossible for anyone to fall down.

Over the past half decade, the Dropkick Murphys have grown into that biggest of draws: a specifically regional group with a national ballast. Founded 10 years ago in Quincy, the Dropkicks early on hitched their wagon to the mythology of the South Boston community, and of Ireland's folklore. Historically, that mythology has included the strong ties of family and church, and also poverty and internecine violence; original frontman Mike McColgan stirred in punk noise, and made it a call to arms.

Now, with a rejiggered lineup that includes only one original member - Casey - the band has streamlined itself for optimum message delivery. "The Meanest of Times," an album released last September, is pure roar, full of odes to loyalty, love, vice, virtue, and "The State of Massachusetts."

On Sunday, singer Al Barr, clad in a black T-shirt, paced the front of the stage, growling through a good chunk of "The Meanest of Times," interspersed with the biggest hits, including the Red Sox anthem, "Tessie." Barr's voice has the effect of flattening a tune, and songs like "Jailbreak" - shared, vocally, with Casey - can flag.

But the occasion was big - St. Patrick's Day eve - and the crowd was hungry, and the pacing was fast. Highlights: the arrival of Stephanie Dougherty, of local outfit Deadly Sins, for a frenetic version of "The Dirty Glass," and the off-kilter rag of "The Gang's All Here."

"Leave your worries at the door," Barr and Casey shouted, allowing the fans to deliver the next refrain: "When the going gets tough, I know my friends will still be there."