Born in Alassio, a Province of Savona, Simonetti studied piano at the Santa Cecilia Conservatory in Rome.

[1][2] In 1953 he moved, with his family, to Brazil, where he found immediate success as musician, composer and entertainer, hosting a long running television program, Simonetti Show, which lasted for 147 episodes;[1][2] thanks to his popularity he was made an honorary citizen of Brazil and was introduced into the "Candido Randon da Silva" order.

[2] In 1964 he came back to Italy, where he joined RAI television, making his debut in the show Chitarra, amore mio.

[1][2] He was active as a television and radio host (often paired with Isabella Biagini), as a film composer, and even an occasional actor.

[2] His film scores include Macumba Love (1960), Special Killers (1973), Il magnate (1973) and Per amore di Cesarina (1976).