 Complete the following phrase:  Born in Turin, Avogadro debuted in the late 1960s as the vocalist of the short-lived vocal group . After the group disbanded, he started a career as a lyricist, getting his first hits in collaboration with Sandro Giacobbe in the early 1970s. He was a usual collaborator of Mario Lavezzi and Oscar Prudente. In 1983 his song Margherita non lo sa ranked third at the 