My band had a performance yesterday. We have three saxophone players. One of plays only Alto saxophone, one of them alternates between playing Alto, Tenor and Baritone saxophone and the last plays both Tenor and Baritone saxophone.
The second two kept swapping each other's instruments or one of the other saxophones they had in the background. So at one point we had to wait for them to change while the rest of us were all ready to start playing the next song.
So, trying to make it less awkward for the audience I turn to them and I says 'I'm sorry, they're just playing ... Musical Instruments'
I'm still giggling about it.