problem finding music on sd card

Phone: LG Optimus F7
Carrier: Boost Mobile
Problem: I transferred my iTunes music folder from my external hard drive to the SD card on the phone. Most of the music plays fine in the music player on the phone, but there are some songs that I can't find. I can't locate them on the phone by song, artist, or album, yet when I connect it to my computer to search for them, they're exactly where they should be.