I have always read "All Yanagisawa metal mouthpieces feature square
chambers...". I just scored a very vintage Yani soprano piece marked
'7' and measuring .059...the chamber is a very traditional squeeze
throat with a slight rollover. At the base of the squeeze it is round
and opens abruptly into the shank ID, just like most other soprano
mouthpieces. Is this different than modern ones? If not, what do they
mean by square chambers?