My dd sounds beautiful on a euph but horrendous on a cornet even though the fingerings are the same.
I can produce a consistant quality of sound on both
The National Festival of Music for Youth (aka mfy) is well worth a trip to - it's at Birmingham over quite a few days, so even if you can only pop up for the Saturday I'd recommend it. For a start, all the groups attending will have been selected from the 'regional festivals' held early in the year around the country. The best (allowing for a balanced programme) groups are then selected for the Schools Proms at the RAH. I know a bit about it as I used to run regional festivals & crew for the Nat Fest (when it was at the South Bank) & Schools Proms. I even played at them when I was a nipper (and also entered with a kazoo band made up of my fellow sixth-formers as a joke). The lady who effectively ran the schools proms some years ago is a parent at one of our local grammars