My dad is somehow those very sensitive to supernatural things. There was once when he was a school / company bus driver, he encountered a lot of these @ one of the primary school compound. When he was doing the cleaning @ the end of his day (around 2am+), he heard pianos coming from the school hall. He thought it was coming from the nearby HDB then & started using the torch light to source around where the sound came from.

It was when he started flashing the torch light at the school hall, that he heard a woman voice asking ‘how thing ***’? He ran out from the school as fast as he could. Luckily, he bumped into 1 patrol police on duty & they guided him back to his bus to retrieve his belongings. After then, my mum used to accompany him during some of the nights. But then they did not encountered anything when my mum was around.
[Posted at: Piano Sound In School]