What's shared on the gnutella network is not controlled by an administrator. The files out there are shared by users like yourself. However, there are organisations that spam the network in an attempt to stop copyright sharing. Examples of those sponsored to do this:
Overpeers,
___ MediaSentry,
___ Mediadefender
You will notice such files are all the same size. Simply ignore all audio files below 2,000 KB (2 MB)