As a songwriter, Leon's songs have hit the charts across all genres and have been covered by a diverse range of artists. Ray Charles recorded 'A Song For You', B.B. King had a hit with 'Hummingbird', The Carpenters with 'Superstar' and Joe Cocker with 'Delta Lady'.

The Carpenter's cover of "Superstar", written by Leon and Bonnie Bramlett, went to #2 on the pop music charts. George Benson won the "Record of the Year" Grammy in 1976 for his cover of Leon's song, "This Masquerade", and it became the first song in music history to hit #1 on the jazz, pop and R&b charts.