Solas have become one of the world"s most exciting Celtic bands by combining a respect for tradition with an adventurous musical spirit. On their fourth CD, The Hour Before Dawn, they gently stretch the boundaries of Irish music by adding new instrumental textures and more sophisticated harmonies. Led by Seamus Egan"s flute and banjo, the band whips through the sets of dance tunes with authority and style. John Doyle continues to expand the vocabulary of Irish rhythm guitar while laying down a solid beat that lets the melodies of fiddler Winifred Horan and accordionist Mick McAuley soar. But as good as the instrumentals are, the songs with vocals are where Solas truly shine. The band"s new lead singer, Dierdre Scanlan, has replaced Karan Casey, who left to pursue a solo career. Scanlan is equally adept on ancient ballads like "When My Love and I Parted," where she is accompanied only by Horan"s violin, and contemporary songs like "I Will Remember You," which Egan cowrote with Sarah McLachlan. She has an earthy voice that reminds us that despite the band"s instrumental prowess, the roots of Irish music are in song. --Michael Simmons