What was the title of John Lennon and Yoko Ono's 1968 experimental album?

John Lennon and Yoko Ono’s 1968 experimental album was Two Virgins, formally titled Unfinished Music No. 1: Two Virgins.

The album grew out of an all-night experimental session at Lennon’s home studio in Kenwood, Surrey, on 3–4 May 1968. Rather than conventional songs, it combines tape loops, electronic sounds, instrument fragments, spoken exchanges and Ono’s vocal improvisations. Lennon and Ono intended the “Unfinished Music” series to document their life and artistic relationship.

Its cover became as famous as its sound: it showed Lennon and Ono nude. EMI refused to distribute the record in that form, so copies were issued through Track Records in the UK and Tetragrammaton in the US, packaged in a plain brown wrapper. The controversy led to seizures in some places.

The album was released in November 1968. It failed to chart in Britain but reached No. 124 in the United States. Its follow-up was Unfinished Music No. 2: Life with the Lions.