19 tone patent

All-
I read with amusement and dismay Paul Hahn's reference to the
patent issued to Yamaha for the use of 19TET on keyboards, guitars, wind
and brass instruments. It a sad fact of life that patents are issued
every day for items and ideas in long and common use. If I were to market
a 19TET guitar Yamaha could legally stop me, even though I had been
building them for years before they filed the patent. Luckily,
microtonalism is just a passing fad, and we won't have to worry about
anything like that.

John Starrett
http://www-math.cudenver.edu/~jstarret