Oh, btw, anyone interesting in semitones, and even microtones,
and tuning adjustments on the fly, should look at the Turkish
zither, the canun.

Each string has some six sharping levers, each adding just
a smidgen, and the skilledplayers are flippng the levers
as they play, constantly modulating the tuning as required.

Whether they do this to bring the music into a more
"natural tuning" depending on how the keys modulate,
or whether they do this to drive Westerners crazy,
I don't know. . . .

Cheers,

                         -- Arne Langsetmo