Following on to Bert's point, there are some series that actually turn up the back ground noise to make effect. The simple act of walking down a corridor where the footsteps are louder than the actors voices.
At least the piano did not drown out the actors talking Richard.Nice thought though.
I still remember the organist at Tooting Granada ,but he appeared between films. The organ then used to sink slowly to lower stage level at which point a hail of ice cream cartons would fly through the air to speed his departure.
Al