This is amazing.... just copy / paste this into google:
intitle:"index.of"(mp3|mp4) your.song.title -html -htm -php -php -cf -jsp
where "your.song.title" is the title of the song you want. It tells google to only display indexes of folders that contain songs (mp3 or mp4) with those words in the file name.
Here's a video walking you through it and more: