Adding songs to iTunes from USB thumb drive

A few years back I pulled most of my music from my iPhone and put it on a thumb drive. I'd like to put it back on the phone, but do not want to mess things up. Will this work:

On the thumb drive, the music is in a folder named Music, downloaded this from the PC originally. Can I just copy this folder to the folder iTunes media on my PC? Then if I connect the phone, run iTunes, then sync, it should be back on the phone.

I've included two screenshots of what I have.

Thanks