Can I change my m4p files to mp3?

I've been having problems getting the music on my Blackberry Classic SD card to play in my car. Only 6 or 7 of my songs would work. I've finally figured out that it's because the rest of my music is in the wrong format. Can I change my m4p files to mp3 without wrecking them? If so, can anyone recommend a faster way to do it than going through hundreds of songs and changing them individually?

Thanks!

m4p is the iTunes protected audio format. You'll have to convert them, which you can do with iTunes.

Read this: https://support.apple.com/en-ca/HT204310

If they're really ancient purchases, read this too: https://support.apple.com/en-ca/HT201616