Professional instruments produce superior resonance and a core tone. This means the sound is clear and resonates beautifully, resulting in a darker, sweeter tone. Accurate pitch, loud volume, beautiful body, good sound quality, large sound, and fully exhibiting the characteristics of a brass tube body. Thick-walled tubing, rich sound, smooth airflow, high notes, and beautiful low notes. Each key is individually debugged, resulting in more uniform overall key strength and a more comfortable feel.