A good balanced diet of solid instruction and daily practise is essential to good trumpet playing. If your weekly diet consist of poor instruction from a well intended teacher with a poor sound you will develop and reinforce a poor sound that will lead to long-term bad habits that can be difficult to correct.
If you aspire to have a good open sound throughout the entire register of the trumpet and wish to play all styles of music with ease then you must have a trumpet teacher who can model this for you. When you study with John Piazza Jr. you will have a steady diet of "SOUND INSTRUCTION" that can only come from experience.