I got two mouthpieces with my little Yamaha YR-231 cornet: a Bach 10-1/2CW and a Yamaha 9. I've been using the Yamaha and put my little guy on the Bach. He's starting on cornet because he's small for his age, it's easier to hold, and he gets a better sound on it.
I don't play cornet much, but when I recently tried the 9 again it seemed a lot bigger than I remembered...leading me to wonder if it's a better idea to start kids ages 9-10 on generally smaller mouthpieces than usual, given their smaller chops/face size and undeveloped breath capacity.
Anyone got any thoughts on this? Or any specific experiences or recommendations relating to starting beginners at this age?