How to: Searching MP3 with Google:

“parent directory” mp3 OR wma OR ogg OR wav Scooter Status Quo -html -htm -download -links
–> Google Search

or

intitle:index.of + “mp3″ Scooter Status Quo -htm -html -php -asp -free -download
–> Google Search

or

“index of” + intitle:mp3  Scooter Status Quo
–> Google Search

More links about Searching MP3 with search engines ->   HERE