The star was joined onstage by Coldplay singer Chris Martin, as well as his Take That co-stars Mark Owen, Jason Orange and Howard Donald during the charity show, to celebrate turning the landmark age, in London.
His bandmates took to the stage and sung `Happy Birthday`, then made Gary close his eyes while the 2,000 strong crowd put the masks on sung along with them to the band`s hit `Shine`.
Jason quipped: "I`ve always known what it`s like to be a bandmate. But now I`m a fan, mate! I`ve been watching up there and mate you`re really good! Someone should sign him up."
Gary also received birthday video messages from Elton John and Robbie Williams - who recently rejoined Take That to record last album `The Flood` and will tour with them this summer, but had commitments in Los Angeles preventing him from being in London.
He said: "I`m really looking forward to seeing you, I miss you."
He then added, jokingly: "And just want to put your mind at ease about the tour - I know you`re worried about my mental health. Well, I`m on meds, everything is fine, everything will be really cool. Love you loads."
The show saw Gary sing hits from across his career with Take That as well as a solo artist, including `Greatest Day`, `Like I Never Loved You At All`, `Sunday to Saturday` and `Wondering`, and he admitted preparing the show had been an emotional rollercoaster.
Introducing a track dedicated to his parents, he said: "I tell you what, rehearsing for this gig has been quite emotional.
"Singing some of these songs which I haven`t even heard for years and years. There was one song, it took me about two weeks to get to the end of it. `Nobody Else`. I wrote it for my mum and dad."
After introducing Chris as "front-man of my favourite band" and singing a version of `Back For Good` Gary said: "Chris, God bless you mate. God bless him. He`s so shy. Thank you mate that was absolutely awesome."