16 Rooms

The story would come from the place first, then the people. In either case, a series of rooms: the suites, hallway, boiler room, patio, parking lot, park downtown, storage room, vestibule, laundry room and, perhaps in the end, the common room. 
In every room, a song, and anywhere from one to six people to sing it. 
The figure of the flaneur, if he's still around, will cue us from one room to the next. Of course, the rooms would have to be sequenced to hook their audience into the cumulative story.
Yes, with the place comes the song, and the voices leading to and from. As before, the passage of time would be highly fluid, as I suppose it always is.
My room, her room, their room, our room.
In the random city.

Songs

Lin Manuel-Miranda, main creator of Hamilton, tells a story that goes something like this: He's written his first three songs and sketched a few more. He asks John Weidman, well-known librettist, for advice. What he, LM-M, wonders is whether new songs should  fill out the narrative (re Alexander Hamilton and the first thirty or so years of the U.S.A.) or just go where they will. Weidman advised the latter course, but I think LM-M took both. 
What this story offers me is the notion that if the songs are what I find most interesting about what I'm up to, that's the show. Let them build the story they build. Fill with a spot of flaneur, some wisecracks about aging from Patty's parents, or a twist in the life of the Nurse. And ever in reserve--a trip for two to the rooftop patio of the Oak Floors.

A Number

If Patty plays Three Questions with the nurse after work (for the nurse, that is) one day, both question and replies, and any related chit-chat, would give us who they are. I can see one of them proposing the game and the other accepting, but I'm not sure how it ends. Could lead to other times and places, other characters. 
(Speaking of characters, today I thought of cutting to six--Patty, the Janitor, her Parents, the Flaneur, and the Nurse--plus a chorus/ensemble of three or four. They could do all the songs, convey all the movement, deliver the stories, create the future, love. Maybe.)
What would happen is that one of them, probably the Nurse, would get distracted and end up looking out a window. Patty should have stopped a question or two sooner.