It’s almost impossible to think of a roots music band that launched its career in more high-profile fashion than Gaelic Storm. Before the Celtic / world music group had even recorded an album, they were cast as the Irish “steerage-class band” in the movie “Titanic.”

Given that “Titanic” became the top-grossing movie of all time until 2009’s “Avatar,” that means their “debut” got considerably more exposure than if they had come up the usual way, playing in pubs and clubs.

The group took advantage of being exposed to millions and millions of eyeballs and earlobes by signing a record deal in ’97, the same year the movie steamrolled box office records, and then released their debut album in ’98. The group has released five more albums since then, with another due this summer, and they’ve continued to gig steadily, playing about 125 dates a year.

Many of those have been at Irish music festivals, but they’ve also played some fairly mainstream gigs, including music-themed cruises like The Rock Boat, Ships & Dip and the Cayamo Cruise, where they’ve rubbed elbows with higher-profile acts like Emmylou Harris, Lyle Lovett and the Barenaked Ladies.

The group, who come to The Ark on Saturday for a sold-out show, originally formed in 1996, when Patrick Murphy (vocals, accordion, piano, harmonica) of Cork City, Ireland, hooked up with Steve Twigger (vocals, mandolin, guitar, bouzouki), of Coventry, England. Both had expatriated to the U.S. by then, and their first gigs were at O’Brien’s Pub in Santa Monica, California.

More bandmates were added, and the group’s lineup has seen a few changes in the years since, switching fiddlers a couple of times, adding a drummer and also adding a piper who plays uilleann, highland and deger (electronic) pipes.

The current lineup also includes California native Ryan Lacey on drums and Canadian Pete Purvis on the aforementioned pipes. Current fiddler Jessie Burns, originally from Suffolk, England, now lives in Colorado.

To augment the instrumentation employed by most contemporary Celtic bands — fiddle / pipes / bouzouki / guitar — Gaelic Storm also employs such unexpected instruments / sounds as African drums, trombones, and Cajun-style accordion.

The group’s lively, highly danceable music isn’t “traditional Celtic.” They also weave various world music grooves and other roots music / pop elements into the mix. That has also broadened their appeal, and ensured chart success: Gaelic Storm’s self-titled debut in ’98 hit No. 5 on Billboard’s World Music Chart, and their ’06 effort, “Bring Yer Wellies,” debuted at No. 2 on that chart and at No. 16 on the Internet Sales Chart. And their latest disc, “What’s The Rumpus?,” from ’08, was their most successful effort yet, debuting at No. 1 on the World Album Chart.

“What’s the Rumpus?” was another collection of rambunctious songs, seemingly tailor-made for a wild dance party, filled with characters who run the gamut from roguish to charismatic to mythic. And the storylines draw from the tall tales of Irish and Scottish folklore. One song, though, purports to be based on a true story: Murphy says that the song, “The Night I Punched Russell Crowe” is a true story.

“I think this is some of the best writing we have ever done — everything seemed to come together perfectly for this CD,” says Twigger on the group’s website. “It is the culmination of a great deal of hard work and a barrel of good times.”

The album was recorded in Austin, where the group fleshed out its sound with the help of folks like all-world pedal-steel player Lloyd Maines (the father of the Dixie Chicks’ Natalie Maines and musical partner of Texas country-folk-rocker Terri Hendrix), as well as ‘60s psychedelic stalwart Arthur Brown.

Listen to the Gaelic Storm album “What’s The Rumpus?”:

The band also tapped into the youth market by recording a special version of “Scalliwag,” from “Bring Yer Wellies” — which was then used in two different EA Games Sims video games. The lyrics were actually translated into “Simlish” — the “official language” of the Sims video game world — and then sung in Simlish by the group.

And in another tech-minded move, in ‘08, Hallmark released a special “soundcard” greeting card for St. Patrick's Day featuring the master recording of the original Gaelic Storm song “Kiss Me I'm Irish” from “Bring Yer Wellies.” It was released in both the U.S. and the UK.

One local Gaelic Storm fan who feels a special kinship with Irish music is Declan Creaney — a native of Northern Ireland.

“They’re a great group,” effuses Creaney, who says he’s been following Gaelic Storm for about six years. “They’re just fantastic. Every time I hear their music, it really does take me back to Ireland.

“And their CDs are all top-notch. Their albums are always fun and lively and interesting,” says Creaney. “They’re definitely at the top of the field when it comes to modern Irish folk music. What they do is more of a younger spin on traditional Irish music — it’s more pumped up, which I really like.

“Their songs can song can make you dance, or make you smile, or make you laugh — but at the same time, some of their songs can also bring a tear to your eye. They really do make me proud to be Irish.”

Kevin Ransom is a free-lance writer who covers music for AnnArbor.com. He can be reached at KevinRansom10@aol.com.

Gaelic Storm performing live with Carbon Leaf earlier this year: