Learning clarinet, there is no difference between elementary and advanced mouth shapes! ! ! There is only one mouth shape from beginning to end: place the upper row of teeth lightly at 1 of the mouthpiece patch, completely place the red part of the lower lip on the lower row of teeth, place the reed lightly on the lips, tighten the chin and relax the corners of both sides. This mouth shape is difficult to maintain when blowing, but it must be maintained. Remember: tighten your chin and don't bite your upper and lower teeth!