I had always thought that concerts WERE the ideal thing to list in the "events" section, and that it would be implemented someday later.
Having pics of the event, program booklets, set lists, and links to any published CDs/DVDs of the event would be great, although the majority of the live photos would have to be pilfered from Famitsu or other JP game sites that had press coverage for them.
Oh, and posters / flyers for events would be another good thing to list in such a case.
I've got a
flyer for the 1993 Game Music Festival.