It's sometimes quite amusing when they start arguing minutiae over things they do know about. I remember one band rehearsal a few years back where the rest of us watched as two of our more fluent readers/proper musicians spent a few minutes arguing over whether a particular sequence of three notes in one of the tunes was actually a 'triplet' or not. Eventually there was a pause in the proceedings and someone else piped up, "Look, can we just agree that they're three f**king notes and get on with it..."