It matters not that your embouchure muscles are positioned and set correctly if you do not have a proper opening for the air to pass through, making the lips vibrate properly. So, how can you be sure that the opening or aperture is correct due to the fact that it is not visible to the eye? That is a more important question than most people think. How to be sure your lip aperture is correct for playing trumpet- 1. Can you start a note without tonguing it? You should be able to start any note simply by moving the air…