American folk musicians Ry Cooder and Taj Mahal, once musical partners, have had careers which are at once conservative and innovative, imbuing the best of folk traditions with their own powerful style. In The Unbroken Circle, Fred Metting challenges the musical labels that often bind artists as he explores the inspirational sources behind these two men. Cooder was influenced by ragtime-blues, bottleneck gospel blues, Norteno music, as well as epic folk ballads. Mahal surrounded himself with Afro-Caribbean music, Chicago blues and Hawaiian music. Both of these artists created a collage from these sources, resisting categories and always driving for the emotional center of the musical experience. Metting traces the parallels between the two, in their careers and their musical backgrounds. He demonstrates how American music transcends classification, finding definition in its very fluidity. The result of a study such as this is not only a respect for the earlier musical sources, but also a desire to continue the tradition of adaptation and change. The Unbroken Circle is a book well-suited for music students, American folklorists, and fans of the musicians profiled.