"tried a Zaphoon once and whilst it is good and loud for such a small instrument and does have a saxophone type tone it is the most complex and illogical fingering system I've come across in nearly thirty years of playing woodwind instruments. I take my hat off to anybody who can master this tricky beastie. "


Studying the fingering chart at http://xaphoon.com/Fingeringchart.html, to me it just looks like a fairly normal fipple type Whistle in Key of C (many woodwinds with reeds are transposing instruments set in keys other than C ...) - the sharps and flats are just the normal cross-fingering (and half-holing). Some of the holes are a bit out of place** (for a normal whislte), hence the need for the extra open holes here and there, and the devil would be to fight the reed to get the correct lip pressure - but that should be easy for anyone who has struggled with a bagpipe chanter or oboe surely...

**The back hole setup makes it look more like a recorder type of fipple flute though.

I am not familar with real 'flagolets' - but don't they arrange the fingering with a back hole?