Thanks for posting in the Apple Support Community. I understand you want to know what's happened to your downloaded music once you cancelled your Apple Music membership. I'm happy to help.
When you subscribe to Apple Music, you have unlimited access to all of the songs in the Apple Music catalog while your membership remains active. Once you cancel your membership, you will only have access to music that you've purchased directly from iTunes. If the music that you're missing was purchased directly in iTunes and not downloaded through Apple Music, you can redownload your past purchases You can take a look at the following resources for more information: Take care.