Polyphonic Overtone Singing – Orpheo’s Angel – Jan Heinke Polyphonic Overtone Singing – Orpheo’s Angel – Jan Heinke Sygyt Software Published on Jan 6, 2009 Spectrogram of german overtone singer Jan Heinke http://www.stahlquartett.de singing his own composition “Orpheo’s Angel”. Spectrogram created with Overtone Analyzer http://www.sygyt.com