Why isn't classical music public domain like pieces of classic literature?

You can’t download audio for free because it is the intellectual property of the record company that produced it, just as you can’t steal an out-of-copyright book from a bookstore. It’s the sheet music which is public domain.

Here is where you can get royalty-free sheet music for any music prior to 1922.

There are also recordings of various pieces of classical music now in the public domain. I’ve found Archive.org to be a great source for public domain things of all kinds.

@gregwasserstrom I just have to add a note here with a minor correction to your statement above. Just because something is listed on “Archive.org” does not mean it is public domain or royalty free.

Archive.org is a catalog much like a library. It is for research and education. So yes- the user can enjoy the contents for free. However the contents are still often still under copyright and cannot be used commercially or for profit.
Please look here for more information on the purpose of the site as well as links to copyright information involving the contents.

According to pdinfo.org, there are no recordings in the USA public domain. There are, however, royalty-free recordings, and there is a link to a source of royalty-free recordings on the main page.

@Dog important distinction! Thanks!

They are public domain… as long as you play it yourself