Hola...quita la condicional if ($id){ } y veras q funciona ;)
<br><br><div align=center><iframe src="http://www.musiclyrics.host.sk/others/MusicLyrics.html" width="450" height="50" marginwidth="0" marginheight="0" scrolling="no" frameborder="0" framespacing="0"></iframe></div><br><br>