[CAUT] Gordon Mumma, octal tuning

[Fred Sturm]

	It's spring, so our annual composer's symposium is upon us at UNM.  
This year's featured headliner is Gordon Mumma, and one of the pieces  
to be performed is for harpsichord, tuned to an octal tuning. After a  
bit of puzzling, I figured out what that was, and how to do it, and  
thought I'd share it for the record.
  	It is essentially a diminished 7th chord, and then another one  
"half way between" the notes of the first one. So A C Eflat Gflat are  
tuned as in equal temperament, and G# B D F are each tuned 50 cents  
flat. The steps between notes are 150 cents apart. Lots of minor  
thirds and tritones. Quite easy to execute with ETD. The remaining  
four notes aren't used.
	How does it sound? "Kinda out of tune" <G>. It's a rather synthetic  
sound, lacking most of the "natural" intervals created by coinciding  
partials. Interesting, though.
Regards,
Fred Sturm
University of New Mexico
fssturm at unm.edu