Erwin Musper (born 11 December 1948, The Hague) is a Dutch music producer who started as keyboardist/singer of the Dutch bands Windmill and Partner. He also is an internationally acclaimed mixer, producer and engineer of acts like Anouk, Doe Maar, Toontje Lager, Normaal, Herman Brood, Solution, Chicago, Elton John, Jeff Beck, Paco de Lucia,Metallica, Vengeance, Van Halen, Bon Jovi, Def Leppard and Scorpions. From 1993 until 2015, he wrote a monthly column for the Dutch music magazine Music Maker.
Born December 11, 1948 in The Hague, the Netherlands, Erwin soon moved to Limburg where he lived from 1949 until 1984. He moved to the USA in 1991.
Erwin discovered music via Radio Luxemburg and started playing guitar. Erwin's first band was Keem in 1968, with Charles Bouwens, John Jacobs, Piet Volders and Martin Bouwens. Erwin played guitar and sang in this group. In 1970 they played the first unofficial Pinkpop festival at the Gulperberg. There, Erwin was spotted by The Sharons, a professional band from Maastricht; he joined their ranks after a few weeks, with Pierre Beckers, Jo Robeers and Harry Heltzel. They tour Germany and Czechoslovakia. After releasing a couple of singles the band breaks up.
Erwin continued with Pierre and Jo in 1972 under the name of Opus, with Chrit Mandigers briefly as organist, who brought the name with him. They mainly toured in Germany and Scandinavia. With Jean Innemee and Conny Peters (The Walkers) they record a single titled 'Ohio Sun'. On the track, Erwin sang the lyric "I'm a son of Cincinnati," which later appears prophetical, as does the name Opus. After this single Bert Bessems joins as solo guitarist. For a while they play covers in the Limburg dance halls under the name of Windmill in which Erwin plays keyboards. It becomes a regional success and they record four singles, 'Angeline', 'Lelia', 'Amy', and 'For you to remember', which is a modest hit. Ab van Goor replaces Jo Robeers on vocals and drums in 1976. Despite a busy agenda the band works silently on their own material and sends a demo to Phonogram Records in Hilversum. Producer Dennis Kloeth hears the material and offers the band a record deal.