Instrument change does not adjust key signature for new instrument
I have a part that starts with Bb Clarinet and switches to Alto Sax in a big band chart. The key signature starts out for the Clarinet but when I change instrument to the Alto Sax the key signature in the part stays the same, ie it doesn't adjust to the written key signature for the new instrument.
If I try to change key signature in the part at that point it changes the key for the whole chart (all the parts).
I can't find a way of working around the wrong key.
Switching instruments like this is a common feature in big band charts especially for the sax section.