I found this mp3 file on my computer so I thought I would upload it as there has been a bit of discussion n one of the boards recently about mouthpieces for high note playing on cornet. I am not sure you need anything special. Any mouthpiece will do. This is me playing an arpeggio to double top C on my Wick 4B on a cornet. OK, the top note is a touch flat, but its good enough.