| This trumpet appears to be configured to play in 'A'.
The tuning slide has an extention piece which can be removed to allow playing in 'Bb'.
The valve slides look like those for 'A' also as they have small extending collars fitted. If these collars are NOT removable then it looks like you can only play this instrument in 'A' as it stands.
The simplest analysis is by playing alongside a modern instrument. |