John Maurice Hartman was an American jazz singer, known for his rich baritone voice and recordings of ballads. He sang and recorded with Earl Hines' and Dizzy Gillespie's big bands and with Erroll Garner. Hartman is best remembered for his collaboration in 1963 with saxophonist John Coltrane, John Coltrane and Johnny Hartman, a landmark album for both him and Coltrane.