During the 1960s Duyn was a popular musician; he had performed in many Dutch bands such as "Whiskers" and the "Jay-Jays". He was also active as a Club DJ at various Dutch nightclubs. In 1971 music producer Hans van Hemert invited Duyn to join his new music group Mouth &amp; MacNeal, together with Maggie MacNeal. In 1972 they had their biggest hit How Do You Do, following several successful hits the duo represented the Netherlands at the Eurovision Song Contest in Brighton, with I See a Star that finished third on the night, after 1974 Duyn and MacNeal went solo.