Calling all experienced bone players ...... I realise that I will probably get as many different answers as I do responses but I would be grateful for your help. My son (aged 8) has just switched to trombone from cornet (because it's cooler !!) but I have no idea what size mouthpiece I should give him. He is playing an old straight Bb Getzen trombone, which I would guess is a good 20/30 years old but is in fantastic condition and plays beautifully. Low register sounds great but he is strugling a bit as he goes up the scale. What size / make of mouthpiece would you recommend ?