The Chieftains, who celebrate their 50th anniversary this year, are still the world's best-loved Irish folk band, both for their superb musicianship and their sense of adventure – working with anyone from Mick Jagger to Alison Krauss or Chinese ensembles. Their last album, San Patricio, recorded with Mexican musicians, was their bravest work to date. This new set has a fashionable cast list, but is more patchy. There are songs from Irish and Scottish singers, but most tracks feature the new celebrities of the Americana movement. Some of it works well: there's a romping collaboration with Carolina Chocolate Drops, a thoughtful treatment of School Days Over from the Low Anthem and an upbeat The Frost Is All Over featuring the magnificent Punch Brothers. Elsewhere, they provide classy backing for the Civil Wars, Bon Iver and the Decemberists. The best tracks are towards the end, as the Chieftains play without help, then collaborate with astronaut Cady Coleman on a remarkable recording she made in space using instruments borrowed from the band.