Hi
Iv always found it strange that there is no genre field in a songs data. It would be useful to know when searching for something new to listen to. You could also group and search songs by genre.
Iv worked on sites and databases before and I don't think it would be too hard to implement (although I don't know how you have your system set up). The only issue could be getting all the artists to fill in the data themselves.
Hope you think about it.