A new David Bowie box set of vinyl singles includes two early versions of the classic song “Space Oddity” to mark the 50th anniversary of his debut hit.

The nine tracks were briefly made available in December, but have never previously been on sale in physical formats. Titled Spying Through a Keyhole – inspired by lyrics from one of the tracks, “Love All Around” – the set will be released in the spring, with more details to come.

“Due to the nature of some of the solo home demos where Bowie accompanied himself on acoustic guitar, the recording quality isn’t always of a usual studio fidelity,” a statement on Bowie’s website explained. “This is partly due to David’s enthusiastic strumming hitting the red on a couple of the tracks, along with the limitations of the original recording equipment and tape degradation. However, the historical importance of these songs and the fact that the selections are from an archive of tracks cleared for release by Bowie, overrides this shortcoming.”

The statement also outlined what to expect from the two versions of “Space Oddity,” noting of the first, “The lyric and arrangement variations lend weight to the theory that this is possibly the first ever recorded demo of one of Bowie’s most famous songs.” The second, an alternate take including different lyrics and collaborator John “Hutch” Hutchinson, was “originally conceived as a song for a duo to perform.”

Bowie released “Space Oddity” on July 11, 1969, five days before Apollo 11, the first manned mission to the moon, took off. The song reached No. 1 in the U.K. and, on re-release in 1973, No. 15 in the U.S. and featured a then-unknown Rick Wakeman playing Mellotron.

David Bowie, 'Spying Through a Keyhole’ Track Listing
1. “Mother Grey” (demo)
2. “In The Heat Of The Morning” (demo)
3. “Goodbye 3d (Threepenny) Joe” (demo)
4. “Love All Around” (demo)
5. “London Bye, Ta-Ta” (demo)
6. “Angel, Angel, Grubby Face” (demo version 1)
7. “Angel, Angel, Grubby Face” (demo version 2)
8. “Space Oddity” (demo excerpt)
9. “Space Oddity” (demo – alternative lyrics, with John Hutchinson)