For years, the Beatles have been conspicuous by their absence on iTunes and other download sites. And their music has only been available on CDs mastered in the digital dark ages.
Now, at last, newly re-mastered CDs are in the shops, with rumours of a download flood to follow. But what took them so long?
The simple answer is money - and a web of legal complications that has kept generations of lawyers busy.
These days, there are four key players: Paul McCartney, Ringo Starr, John Lennon's widow Yoko Ono and George Harrison's widow Olivia.
Before anything can be done in the Beatles' name, all four have to agree. And often that simply hasn't been possible.
Paul and Yoko have argued about whether the Beatles' songs should be credited to Lennon/McCartney or McCartney/Lennon.
The re-mastered Beatles records are now being released
Meanwhile, George spent years sniping at Paul in public. The two men briefly reunited with Ringo in the mid-90s, but George soon pulled the plug.
Most embarrassingly, George, Ringo and Yoko all sued Paul in 1985, when they discovered that he was making more from the group's records than they were. There was always a rapport between the four Beatles, but nothing endangered it more than money.
Since 1962, all the Beatles' records have been released by EMI. And from the 1970s, EMI and the Beatles' company, Apple Corps, were involved in a series of tortuous legal disagreements about royalty payments.
No sooner would one dispute be settled, it seemed, than another began. It wasn't unusual to find the two sides working together on new projects at the same time they were fighting in the High Court. Now the lawyers are licking their lips again.
Digital downloads represent new legal territory, offering copious room for arguments about how their potential earnings from MP3s should be divided up.
And there's an additional complication. The leading player in the download market is iTunes, run by Apple - a company that just happens to share the same name as the Beatles' own business.
The Beatles have sold between 600m and one billion records, cassettes and CDs worldwide.
The official figure for US record sales stands at 211m
The first 50,000 copies of the new box set have already sold out in the UK
The Beatles first heard about the Californian computer buffs in the late 70s, and immediately sued them. Two further cases followed, the most recent triggered by the launch of iTunes - breaking an existing agreement, the Beatles claimed, that the Americans would keep out of the music business.
When the dust settled, Apple claimed victory, before the two sides finally agreed a peace deal.
What everyone has been waiting for is something as rare as a simultaneous eclipse of the sun and the moon: a time when the four Beatles (and their widows), both Apple companies and EMI are all on the same side. Now it might finally have happened - leaving pundits to debate how much money the delay has cost everyone involved.
Some people still aren't happy. The new CDs have none of the bonus tracks found on most other reissues.
What's more, they're anything but cheap. For decades, fans have craved the release of the original mono mixes of the albums - the versions that the Beatles themselves originally approved.
Now, at last, they're in the shops - but only as a boxed set retailing for £200+, or around £20 a disc. It's a bit like Santa turning up and expecting you to pay for your Christmas presents.
So what exactly are we celebrating? It is 40 years this month since John Lennon told his fellow Beatles that he was leaving the group, but there's no mention of that sorry anniversary in the publicity campaign.
A new computer game allows fans to play along with the Beatles
What's really being honoured here is the Beatles' remarkable music - and their equally remarkable earning power.
Like Coca-Cola, McDonalds or (indeed) Apple, the Beatles is a brand with worldwide clout. As album sales sink lower every year, only the Beatles could drag buyers into the shops to purchase music that they probably already own.
But the real challenge lies ahead. For the record industry, the Beatles' catalogue is virtually the last crown jewel in the vault. If, as is widely expected, it is finally made available for digital download, then you can guarantee that it will also fuel a huge illegal market in unauthorised MP3s.
Safeguarding the Beatles' music is going to keep another generation of lawyers in Porsches. But one question remains: what can the Beatles - and the record business - do for an encore?
Peter Doggett's book about the break-up and afterlife of the Beatles, You Never Give Me Your Money, is published by The Bodley Head on September 14.
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