u have to got wifi to download the songs 1st. i figured that out as well.

no need to set permission to 755. just make sure before u launch TTR, u have wifi turn on, then go to download tracks and download them, not many, but just 8 i think. for using mp3, its rather tedious, u have to use finder, locate ur songs in /library/ and copy to /TTR, then tap a few times on TTR, restart. but when u copy songs from mp3, the file name is not given, its in something like SHPT2.mp3. so u have to figure out one by one. which i give up in the end.