[4] The lead single released from the album was "Valleys of Neptune", on February 1, 2010, followed by "Bleeding Heart" on March 1;[5] music videos were produced for both songs.

The majority of the tracks on Valleys of Neptune were recorded in early 1969, while Hendrix was experimenting with songs for his unfinished fourth album, following the successful release of Electric Ladyland in September 1968.

[16] In Rolling Stone, critic Will Hermes found the music beautiful and exciting, while writing, "Are these tracks 'finished' as Hendrix would've intended?

[14] Greg Kot, writing for the Chicago Tribune, called it "a sharp snapshot of a musical genius in the studio during a period of transition".

"[17] In the Los Angeles Times, Ann Powers was less enthusiastic and felt "fans will be fascinated by these bluesy riffs with the Experience, but this album of unreleased material from the archives doesn't convey much that was unknown.