How did Szpilman 'keep quiet'?

Obviously he wasn't supposed to make any noise that would get people's attention. He failed to do that in the first apartment obviously when he accidentally broke all the plates. But I think from the outset, the idea was to just not attract any attention to the apartment where he was hiding. It made me think of all the ways in which he might blow his cover. I thought there being a piano in the second apartment would eventually blow his cover. He was very lucky that none of the fighting that took place during the Warsaw Uprising took him out, because his second apartment was solidly in the thick of it.

He only had the clothes he stood in and what washing up? I think he might of done his no; 1's and no; 2' s in the apartment. If there was not much food, you won't have to go, that much.

Szpilman only stayed in his first hiding place for a few days before he moved on. While hiding in the city, Szpilman had to move many times from flat to flat. Each time he would be provided with food by friends involved in the Polish resistance who, with one or two exceptions, came irregularly but as often as they were able. These months were long and boring for Szpilman; he passed his time by learning to cook elaborate meals silently and out of virtually nothing, by reading, and by teaching himself English. During this entire period Szpilman lived in fear of capture by the Germans. If he were ever discovered and unable to escape, Szpilman planned to commit suicide so that he would be unable to compromise any of his helpers under questioning. During the months Szpilman spent in hiding, he came extremely close to suicide on several occasions, but never had to carry out his plans.