[JACKinBeantown]

Very well put, but (with all respect) not very well thought out. Look at the original setting of Grand Central. It has a roof covering the whole thing with windows on the top sides. Before it was surrounded by taller buildings, amazing shards of light came shining in and illuminated the place with an ethereal quality. That was 100 years ago. You don't think an architect with a sense of imagination and design could come up with a design using today's technology that could hold a MSG on top of a Penn Station and meet all those demands while creating something great? I bet Santiago Calatrava could do it... or many other architects who are creating masterpieces around the world.

The fact that MSG is shaped like a cone on the inside (basketball court surrounded by rows of seats) would allow for an angled ceiling below, thus allowing plenty of light to reach the new Penn Station. That's just one thought.