It used to be that everybody had one: A Polish/Ukrainian/Jewish/Italian uncle who embarrassed you by playing the accordion at family functions. After all, weren't those things just for Mummers?

Times are changing: Liberty Bellows, the one-stop accordion shop and school in the Italian Market, is moving in February to get a bigger showroom and a performance space. In the last 10 years, the 64-year-old Acme Accordion School in Haddon Township - yup, there is one - has seen a steady increase in students in their 20s. And as Bruce Springsteen and Arcade Fire incorporate accordions into their repertoire, the squeeze box is turning into a tool of cool.

"I wouldn't say it's tough being the only guy in the room playing accordion," said Dan Nosheny, who started playing 20 years ago at age 13 to emulate his favorite accordion-using indie band, They Might Be Giants.

"If anything, it helps me to stand out" - useful in a business where audiences give 10 seconds of undivided attention before going back to their conversation at the bar. Nosheny, who goes by "Neon and Shy" on his debut CD (I Don't Want to Be Your Friend), has witnessed in the last two years his instrument's losing its former stigma, especially compared with when he was growing up - "now that bands like Beirut and the Decemberists are adding it to their sound and giving it street cred."

Lately, that street cred has led to increased studio work for Nosheny as more local musicians ask him to sit in with them. His regular gig at Zen Den Coffee in Doylestown gets repeat customers who bring their friends along. Plus, Nosheny has been getting more Philly gigs - his next is Thursday at Connie's Ric Rac.

To his credit, Nosheny did get a first date by introducing himself as an accordionist, and also once used the line: "Do you want to come back to my apartment and I can play the accordion for you?"

At one time, accordion players were cool without question.

"Squareness isn't inherent in the accordion," says ethnomusicologist Marion Jacobson, author of this year's Squeeze This!: A Cultural History of the Accordion in America.

In fact, accordion players such as Guido Deiro rose to vaudeville stardom in the first half of the 20th century, reaching cultural-icon status. Deiro married Mae West and was written about in gossip columns, said Jacobson.

Philly holds special status in accordion history, as it was home throughout the 1940s to the nation's most esteemed accordion ensemble, the Philadelphia Accordion Orchestra. And Philly's Jacob Neupauer, that band's leader who died last year at 93, trained classical and avant-garde accordionists such as local native William Schimmel, credited as one of the chief architects of the current accordion revival.

If the '40s and '50s were the accordion's commercial heyday (it never went out of style within immigrant communities), most folks point to Lawrence Welk and the Beatles for killing the accordion: "Welk with cheesiness; the Beatles, with electric guitars," says Jacobson. "When the Beatles craze hit, the accordion supposedly floated away in a sea of irrelevance."

Its decline was also the collaborative effort of people who willed it out of existence, she said. "I interviewed lots of former accordion players - mostly males in their 60s - who complained that the accordion made you look fat or pregnant and wasn't much help for getting the girls."

It also didn't often sound as mellifluous as it should. "Accordions have 3,000 moving parts," says Liberty Bellows owner Michael Bulboff. That's his way of explaining why listeners over the years got turned off the accordion: Difficult to maintain, it often goes out of tune.

Of course, the accordion has always played a central role in Tejano/conjunto music, klezmer, and Cajun/zydeco.

"German immigrants spread the button-accordion tradition throughout the Midwest and the Southwest, planting the seeds of polka in the Midwest and Tejano/conjunto culture in Texas," writes Jacobson. "It is an instrument that has proven itself to be portable and accessible across class and economic lines - the people's instrument."

Kim Tice, a Philly-based accordionist who has played with big local acts Johnny Showcase and Philly Blocco, points out that the same ethnic identification that made her squeeze box popular in the first place is what is creating its resurgence.

"The accordion is so rich with cultural history for the Irish, Russian, Mexican, Haitian, French, and Italian communities," says Tice, who also teaches and repairs accordions at Liberty Bellows. Tice has been playing the instrument for seven years, first inspired by seeing a street ensemble with two accordionists. "I thought to myself 'Wow, I wish I could do that.' So I went out and bought one - a huge Russian one from the '60s. I liked the challenge of playing what seemed like a mystery."

Liberty Bellows, a colorful cluttered space crammed with vintage accordions, new instruments, and the arcane tools of the trade, was started in 2005 by Bulboff as a hobby in his apartment at 18th and Sansom Streets.

His father, who died when Bulboff was 5, initially played the squeeze box but changed to guitar during the '60s. "I found his accordion in the attic and fell in love with it. The instrument chose me."

With requests for lessons and sales growing, Liberty Bellows moved in 2010 from his apartment to South Ninth Street, where it now sells several accordions a day (in person, as well as through its website), for $200 to $15,000 apiece. Liberty Bellows holds three regular group lessons - for beginners, for intermediate players, and for an all-accordion ensemble with formidable chops. "We have 10 to 20 students that take lessons regularly but we also offer short-term, crash-course lessons and other ad-hoc workshops," says Bulboff.

Stanley Darrow and his wife, Joanna, have owned the Acme Accordion School in Haddon Township since 1948 and have witnessed the ups and downs of the instrument's popularity.

"At our lowest point, about 15 years ago, we had between 45 and 50 students," says Joanna Darrow, a professional accordionist. "Once the accordion lost the stereotype of solely being for the polka, now we have at least 75 students a year and counting." They range from beginner children to adults with experience to professional players who join the Darrows in their accordion club and Westmont Philharmonia Accordion Orchestra.

Growing sales and student interest, as well as a desire to create an all-accordion performance facility, will take Liberty Bellows to 614 S. Second St. next year.

Does the accordion's new popularity mean those who have mastered it have groupies?

"While playing accordion may not make you a chick magnet," Bulboff says, "a sophisticated lady would be hard-pressed to resist a romantic tango or a sultry French waltz."