She may press a button, but it'll be dignified

Music Live's Bill Morris On the Queen's role

Anyone who has not had a letter by then is almost certain not to have seats for the free events.

And it has been announced that among the musical events will be a co-ordinated UK-wide rendition of the Beatles' classic All You Need Is Love

The Queen will signal the start of the musical relay which will involve musicians in 21 locations as part of a major BBC event.

Later in the day on 3 June, Sir Paul McCartney will round off the concert at Buckingham Palace with the song.

Nationwide performance

The song was commissioned 35 years ago by the BBC and was performed as part of a global broadcast in 1967.

This year's event - part of the BBC's annual Music Live - follows the nationwide performance of Perfect Day in 2000, led by Lou Reed.

Almost five million balloons, printed with the words of the Beatles song, will be distributed by National Lottery outlets allowing people to join in with the singalong, broadcast on radio and TV.

The Queen will be in Slough, Berkshire, to begin the song, with musicians elsewhere picking up a cue from the BBC broadcasts and each joining in after one verse.

Bill Morris, festival director for Music Live, said: "We're still discussing how the Queen will begin it.

African drumming

"It might be that she just gives permission for it to start, she may press a button, but it'll be dignified.

"We will have the cast of Evita in one location, African drumming, and the Turkish Beatles Orchestra at other points around the UK."

The two June shows will present some of the biggest names in pop and classical music, to celebrate the 50th anniversary of Queen Elizabeth II's accession to the throne.

The Prom at the Palace, on 1 June, stars cellist Mstislav Rostropovich, sopranos Dame Kiri Te Kanawa and Angela Gheorghiu, tenor Roberto Alagna and the BBC Symphony Orchestra and Chorus conducted by Sir Andrew Davis.

Stars appearing at the Party at the Palace on 3 June will include Sir Paul McCartney, Sir Elton John, Queen, Tony Bennett, Eric Clapton, Phil Collins, Aretha Franklin, Tom Jones, Sir Cliff Richard, S Club 7 and Will Young.