I wrote to the Guardian and got this reply:

"Dear Dave,

Many thanks for your email with regards to our classification of reviews.

Although we are aware that the system of classification for live reviews is not ideal, and we know that this broadbrush approach will inevitably mean that some round pegs are squeezed into square holes, we have decided to stick to these musical classifications: pop, jazz, opera, world music and classical.

With best wishes,

Aster Greenhill
on behalf of

Dan Glaister
Arts Editor
The Guardian"

Anyone want to argue that English Folk would be better in the "World Music" category? Or maybe classical!