I also wonder what would have happened if it were an instrument other than violin. I've long been an orchestral musician myself, and I'm one of a great many people who feel unaccompanied solo violin sounds scratchy and annoying (or thin and lacking in context at best), no matter how skillfully it's played. A really great cellist, however, would grab my attention much more effectively. Or imagine a top-notch bassoonist launching into Rite of Spring out of nowhere. I'd stop to listen.

I agree. My dad loves solo violin, and I personally don't care for the sound. I definitely prefer a cello or someone playing a woodwind.

Alto sax is my personal favorite solo instrument.

Great point. When I was rushing through Grand Central trying to get done with my commute, I hardly paid attention to any action that would otherwise be super interesting to watch/listen to. Now, GC has a huge tourist crowd throughout the day especially this time of the year. If you do this experiment in GC now, I am pretty sure you'd attract a huge tourist crowd, and get the commuters mad too, because you'd be blocking their way.