Hello there! I'm 15 years old and have recently started to play the trumpet after playing the cornet for 9 years. I don't have the best sound on trumpet (much better on cornet) and not the best height. Anyway, I'm thinking of playing baritone/euphonium (playing the euphonium part on baritone) in the Home Guard Youth Band of my county. But my teacher and band director says it a bad idea and that it will destroy my trumpet/cornet playing. Is this true? What I've read on the internet it differs from people to people. I've been playing trombone (not seriously) for half a year and it haven't had any bad effects on my playing on high brass (I have a better tone on the cornet now). So what do you think about switching between baritone/euphonium and trumpet/cornet?