I've got a similar problem. Neither Ringtone Maker nor Ringdroid will recognize the music that I've loaded on my Galaxy Nexus - at least without some work. I uploaded from iTunes using Google Music and made all music available offline. Neither program found the music. I finally got Ringtone to view the music files after connecting to my PC and locating the files using "Browse" and going into the /sdcard folder (arriving at /android/data/com.google.android.music, etc.). I can now see all of my music files, the the names of the files are meaningless (/1.mp3, /10.mp3). Short of testing each one out, I don't see how to get Ringtone Maker to view these songs with the normal song names. Any suggestions?