LONDON ? Musicians, actors and other celebrities paid tribute in London on Sunday to Boyzone star Stephen Gately whose death last month at the age of 33 shocked the pop world.

As crowds of fans gathered in pouring rain outside a theatre in London's West End, stars filed inside for the private concert, including fellow Boyzone members Ronan Keating, Mikey Graham, Keith Duffy and Shane Lynch.

Gately's parents as well as former prime minister Tony Blair's wife Cherie attended the event, reportedly organized by the singer's partner Andrew Cowles.

Duncan James and Lee Ryan from boyband Blue also attended along with former Olympic champion ice skaters Christopher Dean and Jayne Torvill.

Pop singer Chesney Hawkes said he was in a daze after his friend's death.

"I am just still walking around in a daze really -- such a shock, so young, so vibrant, such a lovely guy. It's just so sad," Hawkes said.

The Boyzone members, who did not speak to waiting media, were due to perform a musical tribute to Gately, while actor Ian McKellen was due to read poetry.

British television presenter Graham Norton was expected to give a short speech.

Gately was found dead in his holiday apartment in Majorca on October 10. A coroner ruled he died from natural causes due to excess fluid in his lungs.

Boyzone enjoyed huge success with six number one singles in Britain, but split up in 2000.

The Irish band reunited seven years later, but their recent 19-date Better tour failed to fill stadiums, despite offers of free tickets.