...
echo "mv "$1" "`dirname "$1"`/""$TRCK" "$TIT2"".mp3""
 mv "$1" "`dirname "$1"`/""$TRCK" "$TIT2"".mp3"
...

output in bash

mv 15 Hail santa.mp3 ./15 Hail Santa.mp3
mv: target `Hail Santa.mp3' is not directory