Plastic Ono Band
Ono and Lennon separated for a time during 1973 and 1974. Lennon still used forms of the band name on the two albums he released during their separation, while Ono's records of the time appeared under her name alone. When they got back together in 1975, Ono became pregnant, and both decided to retire from music to be parents. Their son Sean Lennon was born on October 9, 1975, which was Lennon's 35th birthday.