The Chinese-German (and also Dutch-speaking) filmmaker Minghao Xu made an interesting documentary about his fascination for overtones. Originally the final film to complete his studies at a Film Academy in The Netherlands, it is now enhanced and turned into a commercial DVD, published by Traumzeit Verlag in Germany.

Minghao portrays and shows the music of:

David Hykes
Christian Bollmann
Wolfgang Saus
Danny Wetzels
Hosoo & Transmongolia
Jill Purce

and

Mark van Tongeren

This film is a valuable addition to several existing DVDs (which I will discuss here in the future) with cutting edge visuals explaining the mechanism of overtone singing and the diverging personal interpretations of singers and teachers.

Watch the teaser here:

Read more about the film in German (and order it) at Ming-Art or at Traumzeit.