A bedroom in my home has a musty odor in the closet that permeates throughout the room and hallway. After rainfall the smell is at its strongest, and most detectable. My house is a new build and there is no apparent water damage throughout the room.

I'd suspect mold. Look well around the baseboard for the signs of it. If you still don't see any, it may be in the wall. Is rain getting in some way? Helen Ag.