Chara's quiet, and sort of robotic. Frisk takes a guess.

"Don't think you woke anybody up. But if you did, nobody'll bother us. I'll just say we'll be quieter." Confidence, the same they did their best to radiate when they thought people might've been bad to them.

Well, of course people were bad to them, just maybe not right in the castle.

Frisk peers over their pile. "Oh. 'S that another one?" They point at the smaller cello.