I don't know what the "followings" are, but I can tell you that Tenement buildings had no interest in caring for the people who lived there. Tenement housing had its people share bathrooms, there were no lights(besides the window), and the rooms were small and cramped.
The common answer for this is that it is a joke. He was singing that because he was singing a few bars. This is a wordplay on the word bar of soap, and also on the fact that bars in music are <span>a segment of time corresponding to a specific number of </span><span>beats, so it's a pun actually.</span>
