Hello.
My beginner clarinets are struggling mightily with embouchure much, much more than I've ever encountered in my 23 years. It's as if they are physically incapable of playing in tune.
I'm out of ideas. I've used all the analogies I know. Grandma face, firm up corners, take in more (or less) mouthpiece, make a flat chin, blow a hole in the floor, pull back of the tongue up, etc.
I've talked about bottom lip being a cushion and top teeth must grip the mouthpiece.
I've adjusted the angle of their horn. The bell is not between the knees and in the process checked that their head did not move with the horn as the corrected horn position.
I've reached over and wiggled their barrel, proving to them that it's moving but should not.
I've pushed up on the barrel (gently), thus forcing them to bite down and firm up so the horn doesn't then poke them in the back of the throat. It works but then goes immediately flat again when I let go.
It's the same horns we've been using for years. No other group struggled. All of them have good mouthpieces. Some of them have 5RV Lyres. They all have good Van Doren reeds.
These kids. will. NOT. play. in. tune.
I'm out of ideas. Please help me.