[AC Question]

I have an unlocked HTC 10 running Android 7.0. Much of the phone's contents, especially whatever music is on the phone right now, got moved over by the Phone store tech from my previous phone. Which is to say I don't know how it was done.

When I connect my phone to my PC, Windows 10 shows me only top-level folders named: .data, _nero_sync, airdroid, Alarms, Books, com.economist, DCIM, Download, HTCSpeakData, kindle, Mobile Content Transfer, Pictures, Ringtones, shareimage, and zedge

I notice some have initial caps and some don't, perhaps a clue to what's standard and what's been added somewhere along the line.

What is the best way to move mp3 files from my PC to my phone? The only music player app on the phone right now seems to be Google Play Music. I don't like it; there used to be an HTC Music app, but it no longer exists, consistent with HTC's policy of not reinventing wheels.

[ManiacJoe]

Using Windows Explorer, or a file browser app on the phone, you need to locate the MP3 files on the phone.
Once you know where they are, go there using Windows explorer, drag-n-drop the files to your computer's hard drive.