Eusine isn't one to just give up; he does start bellowing "No you can't!" at the top of his lungs, dragging out the sound as long as humanly possible... But the truth is soon pretty evident.

"Yes you can!" And he looks supremely dejected about it. Why, if he'd known you could use instruments he'd have brought a trombone! The fact you can't sing WHILE playing wind instruments is an afterthought.