Dennis Johnson (composer)
Dennis Lee Johnson (November 19, 1938 – December 20, 2018) was a mathematician and a composer. He is the namesake of the Johnson homomorphism in the study of mapping class groups of surfaces. He is credited as having composed the first truly "minimal" composition "November", which was written for solo piano in 1959 (later revised). "November" is famous for being the inspiration for Johnson's UCLA college friend La Monte Young's 1964 composition, "The Well-Tuned Piano". The work has been painstakingly reconstructed from a 1962 112-minute cassette tape recording, and six pages of the original  score, by the composer and musicologist Kyle Gann, who first performed a four-and-a-half-hour version in 2009 with Sarah Cahill. Gann has produced a new performance score based on the original material that R. Andrew Lee recorded in a five hour version released in 2013 by Irritable Hedgehog Music, receiving good reviews and a renewed interest in this seminal work of minimalism. In 2017 the Dutch pianist and composer Jeroen van Veen released "November" as part of his eight-disc "Minimal Piano Collection", Vol XXI–XXVIII. Johnson gave up music around 1962 and moved into mathematics (working  for a time at California Institute of Technology, the private research university in Pasadena) leaving this one fascinating and influential work that features many of the elements that would later become the basic staples of 1960s and early 1970s Minimalism. Death. Johnson died December 20, 2018, in Morgan Hill, California, from complications of dementia. He was 80.