Information density is the amount of information per unit of
something. For example, a
book with a high information density has a lot of ideas in a given number of pages. A
movie in which not a whole lot happens, and not much is expressed, would have a low information density. An
essay with only one key point but a lot of
supporting detail would have a high information density. Obviously, it's a completely
relative measurement- you can't say that a given song has an information density of 3, but you can say that it has a higher information density than another.
Everything 2 probably has about a medium information density.
I enjoy things with high information densities.