Music Minus One

Music Minus One (MMO) was an American educational music company founded in 1950 by Irv Kratka in Westchester, New York, specializing in play-along albums that omit one instrument or voice for practice purposes. Initially focused on classical releases, it expanded into jazz and other genres, becoming an industry standard with over 1,100 digital recordings featuring world-class musicians. The company was acquired by Hal Leonard Corporation, which took over its equipment, inventory, and music library.