Willem Duyn
Wat 'n rare man
Wilhelmus Jacobus Duyn (31 March 1937-4 December 2004) was a Dutch singer, actor and entertainer. Under the stage name Big Mouth he was one of the members of the Dutch music group Mouth & MacNeal.

During the 1960s Duyns 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 & MacNeal, together with Maggie MacNeal.