Five years on from their debut album, this quietly intriguing Welsh band are back, signed to an established world-music label. The Scottish Gaelic star Julie Fowlis proved that you don't have to sing in English to succeed, and 9Bach's appeal is centred on another fine singer, Lisa Jen, whose cool and exquisite vocals in Welsh (and a dash of Greek) dominate the album. She is backed by a band who mix an often languid wash of guitars, bass, harp and harmony vocals with subtle use of technology, adding loops or dub effects. The songs are all self-written, but fit easily alongside the one traditional track, and there are appearances by a male-voice choir and two members of the Australian aboriginal performance group, the Black Arm Band Company. The a cappella duet between Lisa Jen and Lou Bennett is one of the highlights of this low-key but impressive set.