For the average accordion player - this should be no problem. Just pick up the accordion and:
1. Pull bellows without playing anything (see how loose the bellows are - LEAKS?)
2. If it has shifts - see if they actually work (both hands)
3. Out Bellows - play every note up the keyboard (for each reed - Low-Middle-Hi etc)
4. In Bellows - play every note down the keyboard (for each reed - Low-Midd…