I don't really know much about what Ayn Rand thought about Aesthetics, but it it true that she thought art and other aesthetic areas (music?) are just as objectively definable as values? Well they are values aren't they? In contrast to non-aesthetic values however, I don't think they can be defined. One person may prefer blue to red, another may dislike both. I don't see a rational method of aesthetic judgement, it seems automatic and instant, or an arbitrary decision at most.
I can see myself agreeing with every other part of Objectivism, but if the above is correct, then I can't see myself agreeing with her here. I'm unclear about what is meant by objective aesthetics though.
I agree that aesthetics are a requirement for humans, as I discussed a little bit in the Starting From Scratch thread. However I don't believe there is a way of determining "good art" or "bad music", not for humans as a group, and not even for a single person because one's tastes can change very rapidly.
At present I think aesthetics is a realm of subjectivity, and choices or reactions to art and music are purely arbitrary. Really though, I don't know anything about this area of philosophy so please fill me in.