Sixty Four was released in the United States in February 2004 by Donovan Discs, his own record label.

When Donovan was assisting with the compilation of his first compact disc boxed set Troubadour: The Definitive Collection 1964–1976 in the early 1990s, he gained possession of the original demos.

Two of the songs were released on the boxed set; covers of Tim Hardin's "London Town" and Buffy Sainte-Marie's "Co'dine".

The demo tapes feature an 18-year-old Donovan playing guitar and mouth harp.

His style is remarkably close to that of both Woody Guthrie and Bob Dylan, but the songs also feature a distinct style that further developed on Donovan's first two albums, What's Bin Did and What's Bin Hid and Fairytale.