Ignore audio files less than 2.2 MB or 2,000 KB in size. autogenerated mp3 spam results. Use the junk filter to designate such files as junk. Click on those small files & click the trash can icon. Set Junk filter to show junk results at bottom of window. Also, arrange search results by size: Arrange search results by size (click on link)

Worth checking all the tips thru is this How to find music

WMA are often containing DRM if they have been purchased over the internet which only allows that user so play them.

mp3's do not have DRM.