For those of you not familiar with easy listening or classical music, or those of you who don't know Italian, Figlio Perduto means "Lost Son" and is an Italian adaptation of the Erlkonig poem done to an unfinished piece of Beethoven's music. It's incredibly powerful (those of you who saw the King's Speech also got to hear it towards the end, playing in the background).
So yes, that's the ringtone for Jareth's dad... If that doesn't tip him off, nothing will.
Now... what's up with his hand?
Jareth and Sarah belong to Henson, Lucas, Bowie and Connelly.
Erlkönig is a mythological character and belongs to everyone and no one.
Figlio Perduto is written by Beethoven, with lyrics apparently by Chiara Ferrau.