A Celtic disco. Not so long ago, if you put a thing like that on your poster, you'd have been lucky if even your best friend came along to support you on the night. In fact, you wouldn't have a best friend any more.

But this month, as part of "CeltfestChorcai@UCC", 400 students danced the night away at the Celtic disco. Was there free drink? No, but with every ticket purchased you got your very own Celtfest poster. The event was advertised by students wandering the campus in "Celt" outfits, and the music covered all things Celtic from Horslips to the Corrs.

In the current issue of dSide magazine, the Corrs are refered to as the band Bord Failte would have invented if they didn't already exist. Good clean Irish pop with a bit of fiddle thrown in seems to be the recipe. From B*witched - now enjoying a record-breaking fourth British straight-to-number-one from their debut album - who give us the cupla focal now and again (wharraya loike?) to the Cranberries with that bit of a sean nos lilt from Dolores, people just can't seem to get enough of Irish music.

At a conference on the Celtic Tiger in Maynooth recently, one of the speakers looked at how globalisation has affected the role of culture. "Irish culture is being produced at an amazingly tigerish pace to feed the production of a global culture," Honor Fagan said.

Ireland's new cultural products had, she said, responded to the new distributions of people, technology, capital, media and ideas. Wouldn't bands like the Cranberries balk at the idea of being a cultural product - and deny their music was a response to the demands of the global economy? Art is a funny thing: in a recent interview Dolores O'Riordan describes how a particular song, Bury the Hatchet, was written at a time when she was "very hormonal and confused" - hardly ideal conditions, you'd think, to write a commercial tune designed to cash in on the worldwide yen for things Irish.

And a lot of Irish musicians incorporate "Irishness" into their music because they like it. Whatever you think of the snot-spitting neo-punk antics of the Pogues, Irish music was obviously a genuine source of inspiration, not a ploy to sell records in Japan. Nonetheless, someone has to cash in on the growing demand - and the music industry is currently at pains to package artists as "Celtic".

The Celts are described in Crompton's Encyclopedia as tribal red-haired warriors who were good at curing ham and keeping bees. Very little is actually known about their music; in fact the term "Celtic" applied to music is about 15 years old.

In 1999 it seems hard to find an album or a gig without it. In Britain, a tour of Irish musicians coinciding with St Patrick's Day was called "Celtic Flame" - another tribute to this successful marketing formula. That tour, which included Donal Lunny and Sharon Shannon, at least featured a fair smattering of traditional Irish music. But by what definition, exactly, is Phil Lynott singing Sarah on an album called The Best of Celtic Inspiration?

Obviously "Celtic" in the title doesn't always justify putting on your swirly embroidered frock.