To add to that great piece of info, you can also use inurl, intitle, Index.of, and file extension exclusions for doing all kinds of file level searches. For example:
-inurl:htm -inurl:html intitle:"index of" mp3 "artist.or.song.name"
or
intitle:"index.of" (mp3|mp4|avi) artist.or.song.name -html -htm -php -asp -cf -jsp
...stuff like that.
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