Jon Howard Appleton (January 4, 1939 – January 30, 2022) was an American composer, an educator and a pioneer in electro-acoustic music. His earliest compositions in the medium, e.g. "Chef d'Oeuvre" and "Newark Airport Rock" (1967) attracted attention because they established a new tradition some have called programmatic electronic music. In 1970, he won Guggenheim, Fulbright and American-Scandinavian Foundation fellowships. When he was twenty-eight years old, he joined the faculty of Dartmouth College where he established one of the first electronic music studios in the United States. He remained there intermittently for forty-two years. In the mid-1970s, he left Dartmouth to briefly become the head of Elektronmusikstudion (EMS) (sv) in Stockholm, Sweden. In the late 1970s, together with Sydney Alonso and Cameron Jones, he helped develop the first commercial digital synthesizer called the Synclavier. For a decade he toured around the United States and Europe performing the compositions he composed for this instrument. In the early 1990s, he helped found the Theremin Center for Electronic Music at the Moscow Conservatory of Music. He also taught at Keio University (Mita) in Tokyo, Japan, CCRMA at Stanford University and the University of California Santa Cruz. In his later years, he devoted most of his time to the composition of instrumental and choral music in a quasi-Romantic vein which has largely been performed only in France, Russia and Japan.

Appleton was born in Los Angeles, California, on January 4, 1939, to Jewish parents: Helen Jacobs Appleton (born in Philadelphia, 1908) and Charles Leonard Appleton (born Chaim Epelboim in Kishinev, Bessarabia, July 14, 1900). His mother was employed by Metro-Goldwyn-Mayer and his father by Twentieth Century Fox film studios. His father left his family the year Appleton was born and he spent his first years in Mrs. Bell's (an orphanage) and with his brother (Michael Charles Appleton, born 1932) at Palomar Military Academy. When he was six years old his mother married Alexander "Sasha" Walden (born in Ufa, Russia, in 1897), a double-bass player in the Los Angeles Philharmonic orchestra. He was the greatest musical influence in Appleton's young life seeing that he studied piano, encouraging him to compose music and taking him to multiple concerts. Appleton's parents were true believers in the Soviet Union and active members of the multiple left-wing organizations including the Communist party. In the 1950s both his parents were blacklisted by the House Un-American Activities Committee and lost their jobs. As a child Appleton studied piano with Jacob Gimpel and Theodore Saidenberg but preferred composing his own music rather than playing the works assigned to him (e.g. Chopin, Scarlatti, Prokofiev). However, he developed a deep, lifelong affection for Russian music.

From 1957 to 1961 Appleton was a student at Reed College in Portland, Oregon. These years shaped his future life: he composed for his fellow students who performed everything he composed, he decided to become a college professor and in 1959 he married his first wife, a fellow student, Georganna Towne. Following his graduation from Reed College, Appleton moved to San Francisco, California, where his first child was born (Jennifer Appleton). Simultaneously he studied composition with Andrew Imbrie at the University of California, Berkeley, collaborated with writer Willard S. Bain (1938–2000) writing musical comedies and was employed at the Macy's department store as an assistant buyer.

In 1962–1963 Appleton was the music teacher at the Verde Valley School in Sedona, Arizona, where he conducted the choir and orchestra, taught music theory, history and piano lessons.

From 1963 to 1966 Appleton was a graduate student at the University of Oregon in Eugene, Oregon, where he studied with Homer Keller, Henri Lazarof, Felix Salzer and Robert Trotter. It was there that he assembled a primitive electronic music studio and composed his first works in this genre. His thesis was an orchestral work, After "Nude Descending a Staircase". Most of the instrumental and vocal music he composed at this time used serial technique that he loved to compose. During his years in Eugene he became a lifelong friend of the pianist Gabriel Chodos.

In 1966, on the basis of his early electronic music, he was invited by Vladimir Ussachevsky at Columbia University to study in the Columbia-Princeton Electronic Music Center. He became an advocate for electronic music and became friends with fellow composers Charles Dodge, Emmanuel Ghent and Richard Taruskin.

During 1966–1968 he was hired by Oakland University in Rochester, Michigan, to establish an electronic music studio. When the university officials reneged on their promise, he resigned and accepted a position at Dartmouth College. It was during this year that his son, Jon Jason Appleton was born (a.k.a. JJ Appleton; born April 19, 1967).

At Dartmouth College Appleton's work in electronic music was generously encouraged by the administration of President John G. Kemeny and by a generous donation from Gerald Bregman '54. The Bregman Electronic Music studio was one of the pioneering studios at American universities and became a center for many visiting composers. Two of these, Lars-Gunnar Bodin (1935, Stockholm, Sweden – 2021) and Jean-Claude Risset (born 1938, LePuy, France) became important colleagues throughout Appleton's life. In 1970 Appleton also was influenced by the work of the "father" of computer music, Max V. Mathews and by French composers François Bayle, Beatriz Ferreyra and Michel Redolfi.