User-agent: * 
Disallow:

User-agent: Googlebot
Disallow: /*.mp3$

User-agent: Googlebot
Disallow: /*.mp3$
Disallow: /*.cgi$
Disallow: /*.gif$
Disallow: /*.jpeg$
Disallow: /*.png$

User-agent: Googlebot-Image
Disallow: /