How long for Music app to "see" new music?

Just downloaded some songs from my Amazon cloud to my SD card which I previously set up to be seen on C: and in my Music library. I've also got some music in there already and it shows up in the Music app. The problem is I have no idea how to get it to see this new music. It's been about 30 minutes since I added it, I've restarted the system and restarted the app a few times already to no avail. Is there any way to trigger a re-index?

This is on my Surface Pro btw.

BTW 2, this app is a joke right? Like the real one will be released any minute now?