Sixteen solo John Lennon albums are now available to download on iTunes for the first time after a deal was approved by the late Beatle's widow Yoko Ono.
Lennon's works will be available without copy protection restrictions
Many of the recordings had already been on sale from other digital stores, but they had not previously appeared on Apple's market-leading service.
The deal may pave the way for The Beatles catalogue to appear online.
It follows the end of a lengthy legal battle between the band's label Apple Corps and Apple Inc, which owns iTunes.
Among the albums added to iTunes are Lennon Legend and Acoustic, which had not been available to download legally anywhere before.
"John would have loved the fact that his music will now be available in a format suited to a new generation of listeners," Ono said.
Apple chief executive Steve Jobs said: "John Lennon is one of the greatest artists of our time. We're thrilled to have his solo catalogue available on the iTunes store for the first time."
None of the Beatles catalogue is currently legally available online
The works will be among the EMI songs sold without copy protection restrictions.
The deal follows a similar move by Sir Paul McCartney in May. George Harrison is the only former Beatle whose solo work is not available for legal download.
But his widow Olivia recently said an agreement to put the band's recordings online was "imminent".
In February, technology giant Apple reached a deal with The Beatles to end the 25-year legal dispute over the use of the Apple name.
Under the deal, Apple Inc has taken full control of the Apple brand and will license certain trademarks back to the Beatles' Apple Corps for continued use.
The Beatles set up Apple Corps in 1968 to release their songs and manage their creative affairs.