...speaking of the LUTE, any chance you know where to find it? I'm currently kind of stuck on that part (and by extension the part where I'll need to give it to the bard) for some odd reason :|
SPOILER
You should get 1 key from the guard (who is sleeping) - you have to steal it from him
2. You open the second gate using the switch on the first ground floor (red one).
3. Last gate - you need to approach the jug on the right, get past the guards and open the chests.
PS. Sorry for late, I was watching arifureta.