Plastic Ono Band is the moniker for John Lennon’s band with an amorphous membership (though there were some consistent musicians).
In The Word and Music of John Lennon, authors Ben Urish and Ken Bielen write:
To counter Lennon’s frustrations with The Beatles as a near magical entity, he simultaneously declared that the Plastic Ono Band was both a band with no members and a band where all who heard of it were the members; the band was “conceptual.” Publicity material for the band included plastic boxes with instruments and recording equipment in them, declaring the packaging and equipment to be the band itself.