Willem de Kooning | Willem Dafoe | Willem Blaeu | Willem Janszoon | Willem Mengelberg | Willem Roggeman | Herman Willem Daendels | Willem Drees | Willem-Alexander of the Netherlands | Willem van Otterloo | Willem Schouten | Willem Kloos | Willem Klein | Willem II (football club) | Willem II | Willem de Vlamingh | Willem Buiter | John Willem Gran | Willem Verstegen | Willem van Hoogstraten | Willem van Enckevoirt | Willem van de Sande Bakhuyzen | Willem Sassen | Willem P.C. Stemmer | Willem Frederik Hermans | Willem C. Vis Moot | Willem B. Drees | Willem Abraham Wythoff | Pieter Willem Korthals | Jan Willem Storm van Leeuwen |
In 1963 he formed a quartet with pianist Misha Mengelberg and saxophonist Piet Noordijk which had a number of different bassists and which played at the 1966 Newport Jazz Festival, and in 1967 he was a co-founder of the Instant Composers Pool with Mengelberg and Willem Breuker, which sponsored Dutch avant garde performances.