Marriage Proposal: Christmas/Sinatra Musician/Singer Outdoors

I am traveling up with my girlfriend from Philly in the hopes of turning her into a fiancee. We'll be in the city Dec. 20-22. She loves Christmas music, especially when it's played outdoors, and she always gets really exciting thinking it would be the perfect time for a proposal. Hearing Frank Sinatra songs has the same effect. I thought we might just stumble across some outdoor music players while there who might fill this Sinatra/Christmas need, but I decided it might be a good idea to make it a certain thing. As such, I'm looking for someone play and/or sing some Christmas Songs/Frank Sinatra songs. "Something Stupid" or some old Christmas songs would fit the bill. This gig would be perfect for those who are already planning on performing outdoors somewhere, preferably around Washington Sq. area, for us to "stumble across." I figure we'd stick around for a few songs (3-5) during which I'd pop the question and then be on our merry way. I am indifferent about the instruments. You could be just a singer, maybe you have guitar or piano/soundboard, whatever; just as long as it sounds pretty decent. Open to other suggestions you might have. Thanks and all the best!