When World War II started Nissel was interned on the Isle of Man. There he met the violinist Peter Schidlof and later Norbert Brainin. They played a lot of music together. Then they were set free because they were talented musicians. They studied with the famous violin teacher Max Rostal. There they met the British cellist, Martin Lovett whose wife was a pupil of Rostal. The four men played string quartets together, with Peter Schidlof now playing viola. At first they called themselves the Brainin Quartet, but then Nissel had the idea of the name Amadeus Quartet (Amadeus being one of Mozart's names).