FOLK: Martin Hayes, Olympia, Dublin

There's a sense, among Irish musicians, that Martin Hayes has come out of nowhere to stay out on his own; there's also a sense, among the people who write about Irish music, that there are no more adjectives, epithets or cross-generic comparisons left to be used about him. Comparisons in print to the likes of Miles Davis and Jimi Hendrix cause Hayes to step back in quite genuine humility and usually to mumble some self-deprecating witticism in an unmistakably soft-spoken East Clare accent. If he is indeed on that level of genius, he'll be the first in history to combine it with being an ordinary bloke.

Bearing more outward resemblance to Noel Redding than to Jimi Hendrix - mad haircut and scholarly spectacles - Hayes was born into a Clare family with deep traditional music roots. Moving to Chicago in the 1980s with a series of business ideas that didn't work, Hayes found himself playing music for a living, going through a celtic rock and jazz-fusion phase before realising that, no, just like the business ideas, the public didn't want this either. In 1993, exhausted, he made a low-key album of reflective traditional tunes. The public responded. A second one, Under the Moon, released last year, kick-started a critical acclaim/ cult following bandwagon that continues apace.

The albums, however, show only a glimpse of Hayes's performance magic. The on-stage chemistry between the fiddler and his accompanist, Denis Cahill (not on the records), is truly exceptional. Cahill, from Chicago, is a journeyman guitarist, totally new to Irish music and unencumbered by notions of "how it's done". The names of the tunes are almost irrelevant, for between them they have utterly deconstructed the material to create a vast, spacious soundscape aching with the sores and celebrations of centuries, soaring with the slow-burning dynamics of modern classicists like Part and Gorecki. Seemingly every arts writer and musician in town was there - the entirety of Altan, kings of the trad castle included - sitting in pin-drop silence at the feet of the master. The creaking of his chair could be heard at the back of the 1,200-seat auditorium.

There's a notion that JS Bach was a conduit for the music of God - stirring the soul, rewriting the rules, taking the listener by way of austerity and solemnity to previously unreachable heights. What occurs when Martin Hayes and Denis Cahill lock in together on a stage is, for me at least, on that same transcendental level - way beyond the traditional vehicle and onto a different plane of experience. It would seem that the master of silence has found a business idea that works.