Curmudgeonly critics can easily bemoan the whole idea of a tribute band. The arguments are obvious: it's an easy way to a quick buck; it's a vehicle for musicians who have no creative flair of their own; it's just a multi-medium juke box.
None of these thoughts apply to the musicians of the Australian Pink Floyd Show. It was not about being Pink Floyd, it was about finding the best way to convey the majesty of the Pink Floyd experience.
There were no name checks and no inappropriate showboating after a note-perfect rendition of someone else's iconic performance. You would not expect to be introduced to the individual members of an orchestra after a classical recital and this etiquette was observed here. The night was unquestionably about the music and the lights.
From this perspective, it was magnificent. Comparisons with orchestral concerts are entirely appropriate; these are players at the very top of their game. Steve Mac in particular has absorbed the subtle power of David Gilmour, while vocalist Ian Cattell evoked the angst and bitter rage of Roger Waters with chilling conviction. Emily Gervers' delivery of 'The Great Gig In The Sky', with images of the late Rick Wright shimmering behind her, was one of the emotional high points of the evening.
And yet, and yet. The two best moments of the show came when 'Welcome To The Machine' slipped into a drum-driven synthesiser jam, and when Carl Brunsdon took liberties with Dick Parry's corny old sax solos. When the masks dropped and the musicians shone through, it began to feel like a real gig.
Two points of specific doubt: if you're going to do 'Set The Controls For The Heart Of The Sun', make it loose and collectively improvised, not a one-dimensional guitarasm. And don't bother with the material that came after Roger Waters' departure. Even the Floyd couldn't make it compelling.
At the end of it all, you are left with the delicious memory what it means to be a Pink Floyd fan. For the new generation of Floydians, it's probably the only way to find out what it might have been like to witness them at their best. But if you love what Roger Waters called "rock and roll", you can't escape the gloomy notion that, with patience and a bunch of great technology, you can do just about anything these days, without ever having to take a risk.