Not the only instrument to use Pythagorean tuning   I object to this statement  Since Pythagoras calculated the formula for the musical cycle of fourths and fifths Steel Pans are the only instruments made to follow this configuration  Surely there have been many other instruments designed with pythagorean tuning over the centuries   Furthermore its not even clear to me that every Steel Pans tuning is based on exact  frequency ratios in practice I suspect they may often be tuned to TET