I went up a ladder into a loft area, where a computer was playing music in a composition application. It was running on a Macintosh, and the program was called iRise.
Note
There turns out to be a software company called iRise, though they don't make music products. They do however make a platform for software prototyping. From their site:
iRise simulations are easy to assemble for non-programmers and are so realistic users will swear they are interacting with the final production application. The "drag and drop" interface is easy to master and the final product becomes a visual blueprint for what to build.
...yet nothing on their site looks like what I saw.
This iRise program had an interface which resembled GarageBand, and was playing songs in short segments. You could rate those segments of the song and that rating affected what you and others would hear in the future. So you could say "I don't like this drum solo", and the next time the song played, the solo would be cut and some other song segment would be put in.
I dropped into a console window at the unix prompt and tried to get it to print out the date, it said it was the year 2000. As I was tinkering with the computer, it turned into a cash register and coins scattered everywhere. A guy who introduced himself as Woody Allen came over to me and looked over my shoulder.
woody allen: (amused) "What have we over here? A cash register?"
Frustrated, I held up piles of quarters out of the drawer and offered them to him. He sat down in the chair next to me.
me: "I have no idea what's happening. Can you tell me what's going on?"
woody allen: "I'm afraid I don't have any answers, but I'm overwhelmingly empathetic to your problem!"