On Miero (“Outcast”), Finnish folk group Värttinä’s tenth studio album, producer Aija Puurtinen has focused on the enchanting vocal interplay of Mari Kaasinen, Susan Aho and Johanna Virtanen. On tracks such as “Riena/Anathema” and “Mierontie/Path Of The Outcast,” the singers combine into a forceful, almost sinister whole, declaiming over swaggering bass and drum arrangements. Other tracks, such as “Mustat Kengät/Black Shoes” and “Vaiten Valvoin/I Lay Awake,” showcase their gentler side, with one voice taking the lead as the others harmonize. The band steers clear of the rapidly sung, sometimes shrill harmonies featured on previous releases. Some songs, such as “Lumotar/The Enchantress,” with its opening bass figure that almost sounds copped from bebop, achieve a successful mix of jazz, Finnish folk and world influences. Exploring a range of moods that range from dark to serene, the album plays well as a whole. While the backing band is in fine form, with most songs, aside from a few sung acappella, propelled by a raw mix of drums, accordion, bass and violin, this album shines as a celebration of the human voice.