I'm sure I'm missing something because I've done this on my Nexus 5. I uploaded a music album from my library at home to the /storage/emulated/0/sdcard/music folder on my device. However, no player apps see these files (tried Google Play Music and BlackPlayer). I've refreshed multiple times in both with no avail, also restarted once. Am I missing something? I guess I can do it through Google Play on my computer at home, but I'm old fashioned and want to do it directly, cutting out the middle man.