The mp3 files were made available in conjunction with the broadcast of the composer's complete works on BBC Radio 3 from June 5 to 10. Gianandrea Noseda conducted the BBC Philharmonic in the recordings.
"We hope it will encourage audiences to explore online classical music," said Roger Wright, controller of Radio 3. "This trial was all about gauging listeners' appetite for downloads and the results were astonishing."
Symphonies Nos. 6, 7, 8, and 9 will each be made available for a week starting on June 28.