13 was the second and final single to be released from Madhouse’s second and final album 16, and is the final single to have been released by Madhouse. It was released four months after the album, and was released in the USA only.
The 7" single contains the track Four from Madhouse’s first album 8. The 12" single also contained an extended version of Thirteen, as well as a non-album track, Thirteen And ¼. As with the accompanying album, the single’s name is written numerically (13), while the title track is written in full (Thirteen).
The single failed to enter the charts.