I understand that some instruments, like trumpets, are categorised according to the lowest note they can produce without pressing down any of the keys. What I have never grasped is why it seemed like a good idea to make them play at a different pitch from what is notated. I can see that changing this rule would mean beginners might have to get onto sharps and flats a lesson or two earlier but it would save a lifetime of confusion.
We got bitten by this at church this morning. Unexpectedly, the youth band was supplemented by a couple of brass players. Unfortunately, as we tried to remember which way to transpose the music we took the wrong choice and the players weren’t playing confidently enough to make the mistake immediately obvious.
Next time I need to remember that the pattern is to add two sharps; concert A requires the horns to play in B. Next time I also hope to be better prepared but I still wish that, in the past, the decision had been made to call a spade a spade.