Serenity Caldwell, writing for iMore.com, addressing the FUD flying around the internet on Apple Music and DRM:

Yes, Apple Music has a DRM component. Yes, it sucks, but it’s similar to every other streaming service. No, it does not overwrite the files on your Mac to make all your music DRM-laden. For those Googling in a panic, here’s the deal.

Great post. At the heart of this issue is the thought (incorrect) that Apple somehow adds DRM to any of your music files. Back up your music collection before you get started and you’ll still have all your music/video files, in their original state.