English musician and composer, born 11 November 1956 in Sheffield, England. He was a founding member of the electronic band The Human League, writing and playing on their first two albums and several singles, until leaving in 1980 to form the British Electric Foundation and later Heaven 17 together with Martyn Ware.
In 2006 he disappeared from the band's activities and in 2008 Ware finally stated that Marsh was no longer an active member of Heaven 17.