The Royal Concertgebouw Orchestra together with a Radio Broadcasting station is giving away their own recordings, free downloadable versions in Mp3 format. I am not sure about the quality of the MP3-compression. You have to sign in with name, address, etc. to get an email with an activation link. Click on it and your download session may begin. There are symphonies form Beethoven to Sibelius, etc.

Here is the link

The site is in Dutch, so call Snorlax for any help on this.