Peter Kooij started his musical career at 6-years-old as a choir boy and sang many solo soprano-parts in concerts and recordings. He started his musical studies however as a violin student. He has been an active soloist in many concerts all over the world in the most important concert-halls like Concertgebouw Amsterdam, Musikverein Wien, Carnegie Hall New York, Royal Albert Hall London, Teatro Colon Buenos Aires, Berliner and Kölner Philharmonie, Palais Garnier Paris, Suntory and Casals Hall Tokyo, where he performed with famous conductors like Philippe Herreweghe, Ton Koopman, Frans Brüggen, Gustav Leonhardt, René Jacobs, Sigiswald Kuijken, Roger Norrington and Iwan Fisher. He was invited to record the complete Bach cantatas, passions and masses with the Bach Collegium Japan under the direction of Masaaki Suzuki. Peter Kooij is the artistic director of the "Ensemble Vocal Européen". From 1991 to 2000 professor at the Sweelinck Conservatorium in Amsterdam. From 1995 to 1998 Lehrauftrag at the Musikhochschule in Hannover. Since 2000 Professor at the Tokyo University of fine Arts and Music. Since 2005 professor at the Royal Conservorium in Den Haag. Since 2013 professor at the HfK Bremen. He was invited to give master classes in Germany, France, Portugal, Spain, Belgium, Finnland and Japan.
