Hundreds of white balloons have been released in John Lennon's home city of Liverpool as music fans around the world mark 25 years since his death.
The former Beatle was shot outside a Manhattan apartment on 8 December 1980 by Mark Chapman, who is serving 20 years to life in a New York prison. In a newly released interview, Chapman will describe his "compulsion" to kill Lennon as "like a runaway train".
Other tributes include a concert in London with music stars such as Lulu. Lennon had just turned 40 years old when he was shot and killed in New York.
Paul Weller and Jamie Cullum will also be among musicians paying tribute at the concert at London's Abbey Road studios on Thursday. Badly Drawn Boy, Sugababes and Katie Melua will be among the other artists who will take part in the concert, which will feature re-interpretations of Lennon songs.
BBC Radio 2 will be celebrating the work of the former Beatle later with its Lennon Night between 1900 and 2030 GMT. The transmission will be broadcast simultaneously on Radio 2 and across the US on Sirius Satellite Radio, in Manhattan, New York. A gig will also take place in the New York studios.
More than 1,000 messages to Lennon were tied to the balloons released from Liverpool's Albert Dock at 1200 GMT. You can add your own comments on Coldplaying.com here [Thanks Berrywoman]
James Andrews, nine, from Bournemouth, was one of the youngest fans to take part in the balloon release. He said: "I just wrote Merry Christmas John on my balloon. I love The Beatles and especially John Lennon."Another message read: "Looking around at all that's happening in the world today we need his voice now more than ever! He was the only hero I ever had, from Jim Cushman, USA."
Several other events are planned to mark Lennon's death in Liverpool, the city of his birth. At 1630 GMT a images of the singer will be projected on to the George's Dock building. A civic service to celebrate his life is also due to take place at Our Lady and St Nicholas Parish Church, opposite Pier Head, at 1500 GMT.
Fans will also be holding a commemorative event at Strawberry Fields, in Central Park, near the Dakota building where Lennon lived. A one-minute silence was held at Virgin Megastores in central London at 1100GMT.
It was the first time in the store's history that trading will cease to salute a music artist. A major exhibition on the musician and his work is currently being held in Paris.
In addition to being marked by events and radio broadcasts, a number of television programmes will examine aspects of the singer's life and the circumstances surrounding his death. A documentary about Mark Chapman, the man who killed the singer-songwriter, has already prompted anger from Lennon's family.
The Channel 4 documentary I Killed John Lennon, which will feature recordings of Chapman taped by his biographer in 1990, has been criticised by the singer's cousin, Stanley Parkes. Mr Parkes said the broadcast glorified a murderer, although Channel 4 has denied the claims, adding that the neither the killer or his family had received payment.
Meanwhile, Tom Brook - the first British reporter on the scene following the fatal shooting - will look at the impact of Lennon's life and death in his documentary, One Night in December. It will be broadcast on BBC News 24 at 2130.