Jan Vriend was born in 1938 in Benningbroek, The Netherlands.
Under his father's guidance he started to play the piano at the age of five, soon followed by the clarinet, the violin and the organ. Throughout his childhood he was extensively involved in local amateur music making, particularly with the choirs and bands his father conducted. After completing his military service he received further musical training at the Conservatory of Music in Amsterdam where he studied piano, music theory and composition (with Ton de Leeuw). He also attended a percussion course at the Conservatory of Music in Utrecht and a foundation course in electronic music at the Institute for Sonology. In 1967 he received a grant for studies in Paris where he attended classes by Xenakis at the Schola Cantorum and workshops at the Groupe de Recherches Musicales (ORTF). From 1970 he studied mathematics and related sciences, primarily in view of their application in musical composition.
From 1961-1970 Jan Vriend conducted several choirs, ensembles and orchestras in music ranging from early 15th century to 20th century avant garde. In 1965, together with Peter de Buck he founded ASKO, which started as a student orchestra of the two universities of Amsterdam, specializing in contemporary music, with an emphasis on the music of Webern, Xenakis and Varèse. It has since developed into the well known ASKO Ensemble. Until 1971 he was its conductor and artistic director. He lectured extensively on various topics related to composition and the use of mathematics. In 1971 he presented a radio-series on "different ways of listening to music" together with Jos Kunst, with whom he also engaged in improvising experimental background music to poetry readings and radio plays on Dutch radio. Between 1989 and 1994 he was conductor of the New Stroud Orchestra in Gloucestershire where he now lives and works. Jan Vriend performs only occasionally now as a pianist.