Access music from an external SD card?


Just got my Acer Iconia a500 tablet yesterday, as well as a 32GB microSD card. I used Astro File Manager (free version) to transfer my music files from the onboard memory to the SD card, as well as a few pictures. However, I can't seem to open them in the Music/Gallery apps without searching for them in Astro.

tl;dr how do I read music/picture files off of an external source within the Music and Gallery?