More than 2,000 bed nights have been booked in the past fortnight ahead of the North Atlantic Fiddle Convention.
The festival is now expected to deliver a £3m boost to the economy when it takes place in Londonderry and Donegal.
The live music festival will run from June 27 to July 1, just before the Clipper yacht teams arrive in Derry.
NAFCo programme assistant Maggie Maguire, who operates out of the Magee campus of the University of Ulster, said local hotels and accommodation providers have been busy fielding inquiries for late June.
Convention director Liz Doherty, who lectures in music at the University of Ulster in Magee, said the event was shaping up to be a major success.
“We are expecting visitors for NAFCo to exceed 40,000 and it is estimated it will generate a spend of over £3m for the local economy,” she added.
The full programme is available at: www.nafco2012.com