I built this many years ago (http://techcrunch.com/hearwhere), and shut it down a few years later. As others have mentioned, BandsInTown and SongKick are both in this space, along with MANY others. Before I let the domain expire, I'd get e-mails every month or two either from people wanting me to bring back the service, or from people who were building a new one and wanted advice. I haven't figured out why people aren't satisfied with what's out there.