In 1985, when Freddie Mercury and Queen reigned over Live Aid, it would have seemed unthinkable that within just six years the great showman would be dead, never mind that in 2015 two of his bandmates would tour with an American Idol talent show runner-up performing the old songs. But the unlikely union works.
It helps that Queen’s back catalogue is so formidable that even a two-hour show isn’t long enough to pack in their best known songs (there’s no You’re My Best Friend or – irony of ironies – The Show Must Go On).
Guitarist Brian May and drummer Roger Taylor are now grizzled, grey-haired men, but still pack the showmanship and musicianship of real rock legends, even if this does mean indulgences such as drum battles (with Taylor’s son, Rufus) and guitar solos that presumably require enough electricity to power a small town.
Surprisingly, though, this show succeeds because of Adam Lambert, not despite him. The 32-year-old has said he wants to celebrate the flamboyant, camp, gay Mercury rather than replace him, but he definitely has the Freddie factor. Where the band’s earlier tours with heterosexual, macho, ex-Free, bluesy shouter Paul Rodgers felt wrong, the black leathered, bequiffed, nail varnished Lambert is every bit the showman that was Mercury.
The American sips champagne while singing a camped up Killer Queen draped across a chaise longue and yells We Will Rock You wearing a silver crown. When Lambert claps hands, the audience clap with him, unprompted. His unusually wide vocal range allows him to hit high notes (notably Mercury’s famous one in Somebody To Love) which would normally require the assistance of even tighter trousers.
However, the Indianan is no mere talent show get-lucky. Like Mercury, Lambert paid his dues with opera training, theatre, singing in clubs and performing dance and rock, which has given him the dexterity to tackle a catalogue stretching from thumping grooves (Radio Gaga, Another One Bites the Dust) to blistering hard rock (Seven Seas of Rhye, Tie Your Mother Down).
Being the first openly gay man to go straight to a US No 1 (with 2012 solo album Trespassing) does matter. In more conservative times, Mercury sang about his sexuality by way of codes and hidden double entendres; Lambert turns the same songs into riotous celebrations.
There is poignancy, too, when Lambert sings Who Wants to Live Forever under lighting that makes him look like a ghost and in the touchingly warm reception given to May’s achingly sincere Love of My Life, for Mercury.
Because, in a way, this is still the late star’s gig: a homage to his music. It’s Mercury who provokes gasps when he appears on screen to “duet” with Lambert in a Bohemian Rhapsody so riotous one fears the venue may combust.
“There will only be one Freddie Mercury, ever,” Lambert declares, as people roar approval for “the new boy”. However, in Adam Lambert, the late star’s old bandmates have surely found the right person to honour his achievements.
• At London 02 (17, 18 January – tel 0844 395 4000), then touring. Details: queenonline.com
