John White (5 April 1936 – 4 January 2024) was an influential English experimental composer and performer, renowned for pioneering the early British form of minimalism known as systems music. Born in Berlin to an English father and a German mother, his family relocated to London at the onset of World War II. Initially trained as a sculptor, White's career path shifted towards music after being inspired by Olivier Messiaen's Turangalîla-Symphonie. He pursued formal studies in composition at the Royal College of Music under Bernard Stevens and studied piano with Arthur Alexander and Eric Harrison, while also taking private analysis classes with Elisabeth Lutyens.

White's professional journey began as the musical director of the Western Theatre Ballet, followed by a tenure as a professor of composition at the Royal College of Music from 1961 to 1967. A proficient pianist and tuba player, he composed extensively for both instruments, creating over 150 piano sonatas and numerous works for theatre, including collaborations with the Royal Shakespeare Company and the National Theatre.

During the 1960s and 1970s, White was closely associated with fellow English experimental composers such as Cornelius Cardew and Gavin Bryars, and was an active participant in the Scratch Orchestra. His teaching influenced a generation of composers, including Roger Smalley, Brian Dennis, and William York. White's collaborations with younger composers like Christopher Hobbs and Dave Smith led to the formation of various British ensembles, including the Promenade Theatre Orchestra and the Hobbs-White Duo.

White's musical style was eclectic, drawing inspiration from composers such as Erik Satie, Ferruccio Busoni, and Olivier Messiaen, and extending to electronic pop influences like Kraftwerk. His work was characterized by its experimental and avant-garde nature, often employing indeterminate means and numerical systems processes. In the 1980s, White's interest in electronic music grew, leading to innovative compositions using low-tech toy instruments.

John White was a dedicated educator, serving as the head of music at Drama Centre London for four decades until March 2020. His contributions as a mentor significantly impacted the aesthetic development of numerous British actors and directors. White passed away at the age of 87 in London, with memorial services held in his honor at St Paul's, Covent Garden, and the Round Chapel, Hackney.