The Chieftains may be the most refined and virtuosic of all the Irish folk bands, but Altan is the most exciting. On Island Angel, the Dublin sextet blazes through the instrumental medleys of reels, jigs, strathspeys and mazurkas with a reckless abandon. Not content to merely play the dizzying melodies at demanding tempos, all six musicians seem to lean into the rhythms with an urgency that's thrilling to hear. When the music slows down for a slow Gaelic song by Mairead Ni Mhaonaigh, the contrast with the blistering tunes only heightens the drama of her gorgeous, wistful soprano. --Geoffrey Himes