From 1966 to 1970, Fisher played the organ with the soul / pop band, The Soul Survivors, who in 1967 renamed themselves Love Affair. They had a number one hit single in 1968 with "Everlasting Love", while Fisher was taking a break from the band to complete his final year at Hendon County Grammar school. Between 1972 and 1973 he formed the progressive rock band called Morgan, with singer Tim Staffell (the lead singer of the band Smile, who later became Queen).
From 1973 to 1976, after a brief liaison with Third Ear Band, he joined British rock band Mott the Hoople. Meanwhile, Fisher contributed keyboards to John Fiddler's Medicine Head, and when Mott folded, Fisher invited Fiddler to join the remaining members of Mott in what would become British Lions. From 1977 to 1979 the Lions recorded two albums, and three singles: Kim Fowley's "International Heroes", Garland Jeffries' "Wild in the Streets", and Fiddler's own "One More Chance to Run". In 1980, Fisher conceived and produced the unique Miniatures - a sequence of fifty-one tiny masterpieces album (51 one-minute tracks by Robert Fripp, Gavin Bryars, Michael Nyman, The Pretenders, XTC, Penguin Cafe Orchestra, Robert Wyatt, Ivor Cutler, The Damned etc.). A sequel was released in 2000. In addition he played with Queen on their 1982 tour of Europe, and Freddie Mercury can be seen humorously introducing him to the audience just before the band's performance of "Crazy Little Thing Called Love", on the band's Queen on Fire - Live at the Bowl album.
In 1985, Fisher moved to Japan, and started to make ambient and improvised music. He became a TV commercial music songwriter, including songs written or arranged for Cat Power, Karin Krog, José Feliciano, Zap Mama and Swing Out Sister. Japanese artists he has worked with include Yoko Ono, Dip in the Pool, The Boom, Heat Wave, Shoukichi Kina, Haruomi Hosono and Kokoo. He also scored the Japanese anime/live-action hybrid film, Twilight of the Cockroaches (1987) and the documentary, A Zen Life: D.T. Suzuki (2006).
Starting in November 2003 Morgan performed 100 monthly solo improvisation concerts at the cutting-edge arts/music club Superdeluxe in Roppongi, Tokyo. He called this concert series Morgan's Organ, and has started to release live recordings of the series as downloads. The series ended in March 2013 and has been continued as Morgan's Organ At Home at his personal studio in Tokyo since June 2013.
In 2005, he collaborated with German musician Hans-Joachim Roedelius (of Cluster and Harmonia) on the ambient album Neverless (on the Klanggalerie label).
Fisher has maintained a lifelong interest in photography and in recent years has been holding an increasing number of solo exhibitions of his work in Japan and abroad. He has evolved a technique of abstract photography which he calls Light Painting, influenced by the photograms of Man Ray and László Moholy-Nagy, by pendulum-created harmonographs, and in particular by the abstract cinema of Len Lye, Norman McLaren and Oskar Fischinger. Unlike most light painting, where images are created by "drawing" with flashlights, etc., in front of a camera with an open shutter, Fisher's works are in the main created by moving the camera in front of various natural and man-made light sources (fireworks, sunlight on water, city illuminations, etc.). Many of his light paintings may be seen at his art website, and several were used in the booklet of his March 2009 album release Non Mon, a collection of his most well-known TV commercial compositions (Japan, DefSTAR/Sony Records). His light paintings are on the front cover and in a seven-page spread in the Winter 2010 edition of Artworks Magazine (Carmel, California). In Spring 2014 they occupied 20 pages of the photograph magazine Victor published by the Hasselblad camera company. He exhibited in the spring of 2013 at the Hasselblad Gallery in Tokyo.