American Singer canaries are judged on their song only.   Although I don’t show American Singers I try and pay attention to the song of each bird.  My original American singer stock came from an American Singer judge.  Each male bird I sell has been listened to seperately, in my kitchen, so I can usually tell the buyer what kind of song he has.  If the bird sings with his mouth open, too loud, or with obvious song faults I don’t breed him.