Donald Leslie, 93; His Namesake Speaker Influenced Music

Donald James Leslie, inventor and manufacturer of the Leslie speaker, which helped popularize the Hammond organ and contributed to the development of electronic music, has died. He was 93.

Leslie died of natural causes Thursday at his home in Altadena.

A fan of church and theater pipe organs, Leslie became enamored with the compact electric Hammond organ shortly after it was introduced in 1935. He first heard the instrument -- engineer Laurens Hammond’s low-cost alternative to the pipe organ -- in the Barker Brothers Furniture Store in downtown Los Angeles, where he serviced Capehart radios.

The small electric organ, Leslie thought, sounded much like a theater or church pipe organ in the vast furniture showroom. But once he got it home he was disappointed with its sound in confined spaces. He started experimenting with devices to make the instrument sound like labyrinthine pipe organs.

Leslie had taught himself mechanics and electronics in a series of jobs, including work for the Naval Research Laboratories in Washington, D.C., during World War II. When he came up with his hand-built Leslie speaker, he offered it to Hammond, hoping for a job, but was rejected.

So Leslie founded Electro Music in Pasadena to manufacture his speaker, which became a popular sound-refining amplifier for Hammond organs and those made by Wurlitzer, Conn, Thomas, Baldwin, Kimball, Yamaha and others. The Leslie also proved useful for portable keyboards, synthesizers and other electronic instruments, contributing improved sounds to jazz, rock, blues, gospel and pop music.

The Leslie helped adapt electric organs for homes and musicians’ small studios, expanding the market well beyond churches and large auditoriums.

Through the 1940s, the name for Leslie’s invention -- two rotating horns enhancing both treble and bass registers -- varied considerably, from Hollywood speaker to Crawford speaker (for organist Jesse Crawford) to Leslie Vibraphone, among others. But most customers referred to it as the Leslie, and by 1949 Leslie speaker had become the universally accepted name.

Leslie acquired 48 patents for the speaker and other musical inventions.

In 1965, he sold Electro Music to CBS, which made it a part of CBS Musical Instruments. By the 1980s, Hammond had finally bought the speaker Leslie offered the organ-maker four decades earlier, and the Leslie is now built by Hammond-Suzuki USA.

Hammond recognized Leslie’s symbiotic enhancement of its product in 1978 with an award for “his outstanding contribution and dedication in making the Hammond-Leslie sound responsible for creating the organ industry.”

In 2003, Leslie, along with the late Laurens Hammond, and Leo Fender, founder of Fender Guitars, were among the original inductees into the American Music Conference Hall of Fame.

Born in Danville, Ill., Leslie grew up in Glendale and lived his adult life in Pasadena and Altadena.

He is survived by his wife of 50 years, Carolyn; a daughter, Jeanine; two sons, Scott and James; a sister, Mary Elizabeth Grime; and six grandchildren.

The family has invited friends to a celebration of Leslie’s life at 4:30 p.m. Saturday at the family home in Altadena. They have asked that memorial contributions be made to the American Diabetes Assn., P.O. Box 1132, Fairfax, VA 22038-1132.