He skyrocketed to fame after releasing a wealth of demo recordings and mastered albums with groups such as the Jimi Hendrix Experience, Gypsy Sun and Rainbow and Band of Gypsys.

NPR: Jimi Hendrix On World Cafe

"Jimi told me the music he had been recording at the time was elementary and he wanted a more intricate sound, " said Mr. Cox, who served in the Army with Hendrix and was a member of both the Jimi Hendrix Experience and Band of Gypsys.

WSJ: Experiencing a New Hendrix Relic