Prevent Voice Memos from playing in Music shuffle

Hmm, not sure what your voice memos are doing in your music collection. Apple has separate apps to manage these now, so they shouldn't get cross pollinated. That said if you select your voice memos in music you can use Cmd+i to get song info, then on the options tab click Skip when shuffling. You might also untick/uncheck such items which will usually prevent them from playing accidentally when you're not shuffling, and may stop them syncing as music to a device.

tt2

I would suspect you have an Apple Music or iTunes Match account. This will match or upload locally stored music to your cloud library which can then be accessed from other computers or devices where you are signed in. See Managing your Mac media libraries - Apple Community for some background on legacy content from iTunes. Voice memos are now added to a separate cloud library associated with your Apple ID. Integrating existing files from your hard drive doesn't appear to be easy, if it is even possible. That said you can backup any files that you want to keep to some other location so they could be played with other media playing apps, e.g. QuickTime, VLC, etc. Once backed up you can remove them from your Music library along with the uploaded copies in the cloud so that they don't interfere with your general listening plans.

tt2

See the section in Managing your Mac media libraries - Apple Community on iTunes Media Organization for an explanation of why you have that final Music subfolder in your path, and how to eliminate it if you want to. In iTunes there would have been a separate Voice Memos folder. Typically any voice memos will have no artist or album information, which might cause them to be organized into an ../Unknown Artist/Unknown Album folder.

tt2