More than 100,000 deleted recordings, including music from the likes of Jacques Brel and Marianne Faithfull, are to be available to download.
Songs by Jacques Brel and Brigitte Bardot will feature
A batch of 3,000 back-catalogue tracks by European artists from the last 40 years will be online by mid-February, said record company Universal.
It will be the first time in years that music-lovers will be able to buy the recordings.
Universal (UMGI) said it aimed to reissue as many as 10,000 albums.
Such a large volume of deleted recordings being made available online in a "concerted, extensive fashion" had not happened before, it said.
Nana Mouskouri will be among the first artists' recordings released
The first recordings available to download will be tracks by UK, German and French artists.
They include Eddie & the Hot Rods, Fairport Convention, Chris DeBurgh, Jacques Brel, Nana Mouskouri and Brigitte Bardot.
"Over the next three to four years, we aim to reissue perhaps as many as 10,000 albums for downloading, which amounts to more than 100,000 tracks," said Barney Wragg, senior vice president of UMGI's eLabs division.
"This programme will offer material that, in some cases, goes back to the early days of recorded music.
"This 'digital archeology' programme represents a serious commitment to go further into the past, and to begin to take advantage of the benefits for artists and for music fans of digital download technology."