While in high school and college, Harmon gigged as a guitarist for the likes of Z.Z. Hill, McKinley Mitchell, Dorothy Moore and Sam Myers. Relocating to L.A. in the early eighties, he worked as a studio musician, then established himself as a writer and producer, crafting songs for the likes of the O'Jays, Freddie Jackson, Karyn White, Alexander O'Neal, Black Uhuru and the Whispers.

While composing and performing music for a movie score, Harmon was finally compelled to pursue his longtime dream to return to his roots and record his first blues project. The result was 2002's Live at Babe & Ricky's Inn, an electrifying testimonial to Mississippi blues. The album showcased the sound at its best and introduced Zac Harmon as a true torchbearer for the "next generation of the blues". In 2004, Zac with and his then band, the Mid South Blues Revue, won the Blues Foundation's prestigious International Blues Challenge (IBC) title of "Best Unsigned Band".

The Blues According To Zacariah reflects his commitment to the blues and to keeping it real, as he takes you "from the pulpit to the juke joint" with such standouts as "That Mighty High", "Who's Knockin'", "It Hurts Me Too (featuring Miss Mickey Champion) and "Comfort of a Man" (with Greg Wright). The Blues According to Zacariah debuted at #14 on the Living Blues National Radio Airplay Chart, with tracks also airing on XM and Sirius satellite radio and the American Blues Network.

The listeners of XM Satellite Radio voted Harmon "Best New Blues Artist" in the inaugural 2005 XM Nation Music Awards. In 2006, Zac Harmon won a Blues Music (formerly W.C. Handy) Award for "Best New Artist Debut" from the Blues Foundation. Zac Harmon was also featured in the June/July 2006 issue of Blues Revue, as one of the 10 artists that represent the future of the blues.