Walter "Wally" Afanasieff is a Grammy-award-winning record producer and songwriter who started out as Whitney Houston's arranger, but rose to success co-writing and co-producing music with Mariah Carey.

Afanasieff is a multi-instrumentalist; he plays drums, guitar, bass, and piano. He performs on most of his recordings (mainly keyboards, organ, piano, bass and drum-programming). In the large-scale arrangement he is known for producing, Afanasieff has worked with many well-known musicians and mixing engineers like Michael Landau (guitars), Nathan East (bass), Dann Huff (guitars), Mick Guzauski (mixing engineer), Greg Phillinganes (piano), and William Ross (string/orchestra arranger and conductor). The main productions took place at Afanasieff's own recording studios (Wally World) in San Rafael, California where he recorded mainly in digital.

Afanasieff spent the vast majority of his career creating music with Mariah Carey whom, he considered to be the exceptional voice, his muse. He traveled and toured with her, playing piano live. He appeared in Carey's home videos talking about their creative process. During 1997's Butterfly album, Afanasieff and Carey reportedly had creative differences and were falling out. They have not worked together since, although on 2001's Glitter, Carey released one of the songs the pair had co-written during the Butterfly sessions, Lead the Way. After Carey's breakdown E! Entertainment interviewed Afanasieff, who spoke highly of Carey, noting her hard work ethic and musical talent.