Clannad bridged the gap between traditional Celtic music and pop. The results were usually an entrancing, enchanting form of pop that managed to fuse the disparate elements together rather seamlessly, earning the band an international cult of fans. After releasing their self-titled debut in 1973, Clannad eventually hit their commercial peak in the '90s with albums like 1990's Anam (at number 46, their best-charting LP in the U.S.), 1993's Banba (which reached the U.K. Top Five), and 1996's Lore (their sole appearance in Ireland's Top Ten). After winning a Grammy Award for Best...