Original: '' Happy Xmas ( War Is Over ) '' is a song written by John Lennon and Yoko Ono and released in 1971 as a single by John & Yoko\/Plastic Ono Band with the Harlem Community Choir .
Simplified: '' Happy Xmas ( War Is Over ) '' is a Christmas song by John Lennon , Yoko Ono and the The Plastic Ono Band .