Revising prepositions: in, on or at?

The idea of recording a song to raise money for the people of Ethiopia started with Bob Geldof and Midge Ure in 1984. Geldof played in a relatively successful rock band, the Boomtown Rats, and was better known for playing the main role in the Pink Floyd movie "The Wall" (1982). Here is Bob Geldof's biography; decide which preposition - IN, ON or AT - best completes each gap in the text.