Marakanetz,
I vaguely recall tinkering with a bandoneon many (too many to think about) years ago. I'm nearly 100% sure that it sounded on both compression and expansion. It may well be that there are variants that work differently, but the one I handled was "bi". Of course, it's also possible that the "bandoneon" that I played was actually a related instrument that was incorrectly identified by the owner that let me have a go at it.
Marty
I vaguely recall tinkering with a bandoneon many (too many to think about) years ago. I'm nearly 100% sure that it sounded on both compression and expansion. It may well be that there are variants that work differently, but the one I handled was "bi". Of course, it's also possible that the "bandoneon" that I played was actually a related instrument that was incorrectly identified by the owner that let me have a go at it.
Marty