Unhappy [Q] Weird happening with my music

I've got a galaxy S4 running on Google Edition 4.4. I have always used MediaMonkey to add my music onto my device, last week I had added a bunch of new songs to my phone (onto the EXT SD card). I went to add some more today and I had noticed a bunch of songs missing according to MediaMonkey. I went onto the device with windows explorer and to my surprise couldn't locate a random chunk of the songs that I put on last week.
Oddly enough the Google music app can still see and play the songs on my device, but according to my PC they do not exist. The only way I can actually view all the missing songs is through ES File Explorer in which everything is in the music folder and seems fine.

View hidden files is enabled, did something mess up when the songs were copied over or what the heck happened?