The monks started the chanting early.

Mera was singing outside, twice. First time he wanted dinner. Second time he wanted to come in, away from the cymbals.

Because in order to reach the lift lobby where his dad would be, he had to walk past the monks.

Another way, of course, is to walk up to the 6th floor, walk across the connecting corridor, and go one floor down to reach his house. I don't think his little paws can cope with such epic journey.