Wikipedia used to list 34 subgenres of heavy metal. These included everything from Christian Metal to Neo-Classical Metal - I'm particularly intrigued by Nintendocore and Viking Metal - so this is indeed a rich and diverse underworld of music that most of us have not been exposed to.
If Maria Miller had her way, the only arts and culture we would ever experience would be the stuff that can establish upfront that it has solid economic foundations and will wash its own face - what a boring world that would be. Have we really got to the point in this country where we only care about things that create wealth?
The fact is that there is no music ever recorded that cannot in some way or another be performed live.