The son of the President of Switzerland, he graduated in agricultural engineering - a field in which he worked between 1938 and 1948.

Musy joined the military briefly as a pilot during the war, and then in 1947 he began his two-wheel sporting career. He raced for Moto Guzzi until 1953, with whom he conquered six Swiss titles in the 250cc and 500cc classes. Cars were his real passion, though, and in 1954 he decided to buy his own Maserati A6GCS two-litre Sport. He claimed a good many victories in the car.

In 1995, after numerous successes on the international stage with the 150S and 200S, he chose to purchase the more powerful 300S. Sadly, on 7 October 1956 during the Salon a Montlhéry Grand Prix in France, Musy lost his life at the wheel of the 200S.