John Lennon's 50th birthday will be marked with a celebration beyond even the slain rock star's utopian vision: his peace anthem "Imagine" playing simultaneously for 1 billion people in 130 countries.

"This idea appealed to me, because not only will we cover the whole world, but also there's something that's very small," said Lennon's widow, Yoko Ono, who will speak briefly before the song is played Oct. 9 at 8 a.m. MDT.Lennon was gunned down outside his Manhattan apartment in 1980.

The 10-minute event will be broadcast worldwide from the United Nations, and will also feature a short introduction by Marcela Perez de Cuellar, wife of the U.N. secretary general.

A taped message from Lennon will be broadcast before "Imagine" is played.