Music Minus One (MMO) was an American educational music company founded in Westchester, New York. The company released play-along albums intended to accompany a melodic instrument (or vocalist) as an aid for practicing.

Music Minus One was founded in 1950 by Irv Kratka, a 24-year-old college student. The company's first recording was based on Schubert's "Trout Quintet" opus, with one of the five ensemble instruments omitted in each of the versions. The release received a full-page review in 1953 in The New York Times.^{[citation needed]}

In the following years, the company released chamber music and jazz "rhythm recordings" utilizing New York. Stan Getz, Hank Jones, George Barnes, Max Roach, Julius Baker, Elaine Douvas, Armando Ghitalla, Stanley Drucker, Christian Reichert have played on MMO recordings. MMO produced approximately nine hundred albums,^{[citation needed]} covering the genres of classical, chamber music, opera, lieder, popular, jazz and religious music.

In 2016, the CEO of the Hal Leonard Corporation, Keith Mardak, purchased Music Minus One.^[1]

• UK Distributors of Music Minus One
• NAMM Oral History Interview Irv Kratka reflects on the development of Music Minus One and the musicians on the recordings, September 13, 2005
• New York Times "Records: Play Along" Sept 13, 1953 review of MMO Trout Quintet recording.