Everyone knows that the record industry has suffered enormously due to plummeting sales. But just imagine what a perilous state it would be in if it wasn't for so-called "heritage acts" like Led Zeppelin whose back catalogue continues to sell by the truck-load.
Celebration Day will ensure that Warners – as well as the already super-wealthy members of Led Zep – will have an extra happy Christmas.
New material from Messrs Page, Plant and Jones won't be in the offing any time soon, but the band's gargantuan fan-base is likely to lap up the next best thing – a live recording of their one-off gig at London's O2 in December 2007 in aid of charities chosen by the late, legendary music executive, Ahmet Ertegun. It would be their first – and to date, last – full-length concert since the death of drummer John Bonham in 1980.
Celebration Day has been marketed to the hilt and was glowingly received when the concert footage was screened in cinemas around the world last month.
Now, it's being released in every manner imaginable: album-DVD combo, vinyl extravaganza, lavish box-set – the list goes on.
Even the decidedly outdated double-album format – reviewed here – is going to receive a whole lotta love from devotees.
Over the course of 16 songs, the band cements their reputation as one of the greatest live entities in the history of rock.
The three elder statesmen still have it – Robert Plant's marvellous vocals roll back the years, Jimmy Page reminds us of what a superb guitarist he is thanks to all those huge and highly familiar riffs, and John Paul Jones's expressive bass enhances his standing as one half of rock's most celebrated rhythm section.
Jones's old sparring partner, John Bonham, may no longer be with us, but here, his son Jason ably fills the percussion breach. His performance is the night's greatest revelation and his playing would surely make his old man proud.
The songs – hugely familiar, yet rendered fresh by the band's urgent performance – are, without exception, brilliantly realised.
Ramble On – never before played life – is a thrilling exercise in blues rock, while Stairway to Heaven remains gloriously moving.
Best of all is Kashmir – an intoxicating nine-minute wonder built around Page's guitar.
Key tracks Kashmir; Ramble On