What tuning of clarinets are most commonly used in 1920's and 40's Swing music.
The tuning of clarinets that are most commonly used in 1920's and 1940's Swing music is meantone. However, a skilled clarinetist can easily alter the tuning of different notes to produce various pitch and vibrato.
I would say flat or neutral.. but I'm a percussionist. I know nothing more than beats and sticking.