A musical, opera or ballet (and other related work types) are performed live and make sense as events, but none of the current event types really fit them (they're not really "concerts" as such). We should add a type for all of them, if we can think of a more generic option for "stuff that involves acting/dancing/other stuff than just a concert", or if not more specific types for the most common types ("Musical/Play", "Ballet", "Opera/Operetta" maybe? unsure yet).