Some estimate almost 50 million songs from 2003 to 2015 have been lost.
MySpace was bought by NewsCorp in 2005 for $580m (£437m).
Throughout the 12-year period, over 50 million songs from 14 million artists were uploaded to MySpace, and now they have disappeared, due to problems encountered during a server migration.
Although it's now a relic from a different era, MySpace was once the king of all social networks and a launchpad for countless musical projects including Arctic Monkeys and Lily Allen.
The data loss followed a server migration, with the company admitting the loss on its website admitting that "any photos, videos and audio files" more than three years old are probably gone for good.
"We apologise for the inconvenience". "Flagrant incompetence may be bad PR, but it still sounds better than, 'We can't be bothered with the effort and cost of migrating and hosting 50m old MP3s'".
On message boards and on social media, the news spurred questions about cloud storage and the reliability of third-party servers.
Despite generating $800 million in revenue during the 2008 financial year, the site was usurped in popularity by Facebook, and has since been sold twice: to Specific Media Group and Justin Timberlake in 2011 for $35 million, and to Time Inc.in 2016.
That same year, MySpace was acquired by Rupert Murdoch's News Corporation for $580 million, and the 100-millionth account was created in August 2006.