Queen guitarist Brian May says at the start of this show that The Freddie Mercury Tribute Concert is to “Celebrate the life, work and dreams of one, Freddie Mercury”.

2013 makes it the 21st anniversary of one of the biggest send-offs in rock ‘n’ roll history. It took place on 20 April 1992 at London’s Wembley Stadium to 72,000 people and a televised audience of approximately one billion. To say it wasn’t an important moment in musical history would be a travesty.

Mercury passed away in November 1991 from bronchopneumonia brought on by AIDS. The Mercury Phoenix Trust was subsequently set up to offer relief to AIDs sufferers and the tribute show was originally designed to raise awareness of the disease.

A star-studded line-up of rock and pop music royalty was assembled. These included Mercury’s surviving bandmates alongside acts like Def Leppard, Extreme, Guns N’Roses and Metallica, who were influenced by Queen, and other artists that Mercury was a fan of, such as David Bowie, Robert Plant and Liza Minnelli.

The filmed version of the performance has been released a few times over the years, but this year it makes its debut on Blu-ray and comes with remastered sound. The name “Definitive” is a bit of a misnomer though, because while the set is comprehensive it is far from complete – with music by Spinal Tap omitted and other artists having their sets cut short.

The proceedings are filled with nostalgia and love for the great man, but this doesn’t save the concert from some truly cringe-worthy moments. Elizabeth Taylor gives us a long, rambling speech about the importance of using protection and says, “Don’t worry, I’m not gonna sing!”

The middle of the show almost turns into a Bowie-fest as he performs “Heroes” and “All The Young Dudes”. But the weirdest Bowie moment has to be a tie between singing “Under Pressure” with Annie Lennox and when he gets down on one knee to recite “The Lord’s Prayer”. Really.

Axl Rose is shrill as he sings “We Will Rock You”, while Extreme frontman Gary Cherone is distractingly hyperactive in his performances.

There are, however, many moments where the guests do Queen’s music justice. The Who’s Roger Daltrey offers a defiant “I Want It All”, while Black Sabbath’s Tony Iommi does a superb job with May on guitars.

George Michael does a beautiful version of “Somebody To Love” with the London Gospel Choir, and Elton John is all great and powerful during his part in “Bohemian Rhapsody”. The finale of “We Are The Champions” is an absolute joy – even in such sad circumstances – lead by Liza Minnelli and the entire cast.

At times The Freddie Mercury Tribute Concert is like the frontman it celebrates. It’s camp, bombastic, colourful and full of theatrics. It also showcases the effect the band had, and continues to have, over music.

There are moments where the concert can be hit and miss, and not every fan will love every rendition of the Queen classics offered here. Nonetheless, there’s no denying that the whole shebang is an excellent farewell. The hodgepodge grouping ultimately works the crowd to fever pitch, with fans singing along to almost every word.

If nothing else, the event supported an extremely worthy cause – something that this release continues to promote.