My guess is some of the music files are fake or worse. Although the following article was written for LimeWire users, the principles still apply for other gnutella program users How to find music & video.
Some of the program locations for settings will obviously be different however.

Some things like, making sure the music file has a bitrate, & if you have a little experience, comparing bitrates versus file size according to the length of the song. If they seem out, then chances are there's something wrong with the file. Spam is deliberately spread across the network by professional organisations in an attempt to prevent copyright file sharing. Knowing how to recognise & ignore spam is something you will hopefully learn with experience.