 Between 1970 and 1972, Carsten Bohn was the leader and drummer of Frumpy, the German "Kraut Rock" band headlined by the Hamburg-born blues singer Inga Rumpf.Bohn was already a fixture in the German music business when, as BERT BRAC, he began composing music for audio story books.The music accompanying the audiobooks became just as popular as the stories themselves.