Altan's evolution as an ace ensemble has made for fascinating observation. Wooed by the big industry players, they've (inevitably) been subtly moulded by Virgin over the past three albums. Slowly, Mairiad Nm Mhaonaigh has been edged towards centre stage, the songs have gradually come to usurp the tunes, and the pitch is very definitely at a wider audience who might be - shall we say - less familiar with the grammar and syntax of the trad idiom. Despite the commercial realities, however, Altan retain their essence, and indeed the more they record, the more it asserts its identity.

There's simply nothing to come near Mairiad's reading of 'Green Grow The Rushes', a long-loved tune now finally reunited with its Robert Burns lyric. Voice, whistle, accordion and guitar meld together with a kind of effortlessness that few musicians ever manage to achieve. What could have so easily been coated in molasses for a mass market instead glistens in an arrangement that's bare-boned but pitch perfect, the essence of restraint.

The tunes are there too. The first few reels set the tone: 'The King of Meenasillagh/ Lamey's/The High Fiddle Reel' is a heady mix of old and new, the last a tune written by Mairiad. Driven by Ciaran Curran's bouzouki, and fuelled by Mark Kelly's fluid guitar, there's enough room between the chords for fiddles and box to swoop and soar with the kind of abandon that comes with the ease of a quintet who can mind read.