The band had added the song to their live set during their tour following the death of Lennon in December 1980. It was intended to be a one off tribute performance at a show in Dortmund on 19th December. It has featured in every Roxy Music or Bryan Ferry solo tour since, including Live Aid in 1985.
Despite a long and successful career this single would be Roxy Music's only number 1 in the UK. The full length version of the song is 6:10 long. A live version can be heard on the Roxy Music album Heart Still Beating (1990)
Source. Viva Roxy Music