Altan, named for Loch Altan in Ireland's County Donegal, has arguably had a wider impact on audiences over the last 30 years than any other traditional Irish band. Their dynamic and warm live performances mix the most touching old Irish songs with hard-hitting reels and jigs, and the band members' interest in and sheer enjoyment of each other musically is apparent even to audience members new to the Irish tradition. For the Irish music enthusiast, Altan has a treasure trove of brilliant moves to offer: the mix of sounds from Donegal with outside influences, the sheer virtuosity of the players, the beauty, delicate singing, and down-to-earth charm of singer and fiddler Mairead Ni Mhaonaigh. Anywhere they go, a concert by Altan is the Irish music event of the year, and you can also pick up a copy of the group’s new book, “The Tunes.”