William Donald Nix (September 27, 1941 – December 31, 2024) was an American musician, songwriter, and producer.

"[2] William Donald Nix[3] was born into a musical family in Memphis, Tennessee, on September 27, 1941.

[4] Nix began his career playing saxophone for the Memphis-based Mar-Keys, alongside Steve Cropper and Duck Dunn.

[2] After relocating to Los Angeles in the mid-1960s, Nix worked as a producer and songwriter with such acts as Leon Russell, Gary Lewis and the Playboys, John Mayall and the Bluesbreakers, and Freddie King, among others.

[1][2] Nix's best known composition, "Going Down," was originally released by the band Moloch on their eponymous album in 1969, and has become a blues-rock standard, having been covered by Freddie King, the Jeff Beck Group, the Who, and the Rolling Stones.