Part of the UK's national music archive could be lost as a result of copyright law, the British Library has warned.
The Sound Archive must ensure old recordings can still be heard
The library's Sound Archive cannot copy audio from fragile or obsolete formats for posterity until copyright runs out.
And Sir Cliff Richard is leading a music industry campaign to extend the copyright on sound recordings beyond the current 50-year limit.
The library said a "significant" part of the collection could "decay and be unavailable for future generations".
The Sound Archive holds more than a million discs, 185,000 tapes and many other sound and video recordings.
It currently collects about 75% of all music released commercially in the UK and also includes plays, poetry, speeches, interviews, and wildlife sounds.
Launching its intellectual property "manifesto" on Monday, the British Library called on the government to ensure recordings are not left to rot.
"Currently the law does not permit copying of sound and film items for preservation," the manifesto said.
"Without the right to make copies, the UK is losing a large part of its recorded culture.
"Many original audio and film formats we hold are becoming increasingly more fragile," the library said, and "face irretrievable decay" if not preserved.
As well as old and fragile formats, the archive must also copy recordings on obsolete formats - such as Betamax and reel-to-reel audio tape - to ensure they can be heard in the future when machines no longer exist to play them.
Sir Cliff Richard's first hits are due to go out of copyright in 2008
The decision on extending the term of copyright should be based on "sound economic evidence and the needs of all members of our economy and society", the library said.
Sir Cliff, along with major record labels and other ageing rockers, wants to extend the term because royalties will no longer be paid for recordings over 50 years old.
He says recording artists should receive the same rights as songwriters, who get royalties for life plus 70 years. His first hits are due to go out of copyright in two years.
But the British Library said it was "concerned from a preservation perspective that any extension will adversely affect our ability to archive sound recordings".