Re Greg Be to B/C boxes and other semitone tunings.

Understanding of the constructions of scales is fine and well if you have an understanding of music theory. To actually play a dance tune effectively on Eb on a B/C box you need to have an embedded muscle memory of the ins and outs and crossovers of the Eb scale. So too for all the other 10 scales apart from B and C major, which as another contributor observed, are relatively intuitive once you've got a basic understanding.   

I've found that learning to play common tunes in obscure keys on the B/C is a great way to improve your dexterity and precision. It doesn't go down well at sessions.

Cheers

AB