Although The Beatles were a quartet, only two of the Fab Four members remain. John Lennon was murdered in December 1980 and George Harrison succumbed to lung cancer in 2001. There have been numerous tributes to both of them.
Lennon was murdered in New York City by Mark David Chapman, who had a been a huge childhood fan of The Beatles. After his death, a crowd gathered in mourning to pay tribute to him in ten minutes of silence as requested by his widow, Yoko Ono.
George Harrison had written "All Those Years ago" before the death of Lennon. The lyrics were originally different, however, upon hearing the news of Lennon's death, Harrison changed the lyrics and rewrote the song as a tribute to Lennon. Surviving Beatles Ringo Starr and Paul McCartney, along with McCartney's wife Linda, and Wings member Denny Laine contributed to the recording.
McCartney recorded his own personal tribute to Lennon, titled "Here Today," on his 1982 album, Tug of War. McCartney had been affected by Lennon's death to the extent that he became reluctant about touring.
In 2006 a selection of modern recording artists released versions of Lennon's songs on a charitable album called Instant Karma: The Amnesty International Campaign to Save Darfur, named after a John Lennon song. Performers included U2, Lenny Kravitz, The Cure, Green Day, R.E.M., Christina Aguilera, Duran Duran, and The Black Eyed Peas, among others. U2 recorded the title track.