This totally contradicts what textbooks have been telling us for many years. I'm sure many people would be surprised to see this kind of usage.

Interested in Language
Please be aware that I'm neither a native English speaker nor a teacher.
This totally contradicts what textbooks have been telling us for many years. I'm sure many people would be surprised to see this kind of usage.
It's really sad to see English being mangled. It's probably the most marred language in history. I will never tell anyone I'll teach that it's possible to say "a money" or "a furniture". I'll stick to the rules set out by prominent native authors and followed by tens of millions of people all over the world.
Talk to Roger Woodham to see what he thinks.
Alexandre from Brazil writes:
I have some doubts about uncountable nouns. Music is uncountable, so it is wrong if you use a before music. What is the correct form to use? Is it possible to use a before an adjective with an uncountable noun?
- I have a beautiful music to show you.
Roger Woodham (http://www.bbc.co.uk/worldservice/learningenglish/grammar/learnit/learnitv283.shtml) replies:
You're quite right, Alexandre. Music is an uncountable or mass noun so we cannot say a music or even a beautiful music. Instead we have to use some or any or, if we want to refer to a single piece of music, we must use a partitive construction such as a piece of:
- I'm going to play you some music by Chopin.
- Have you heard this piece of music that he composed in 1826?
- I don't think I've ever heard any music by Chopin.
Bennevis, this is becoming unreasonable. We have demonstrated that "a music" is fine, meaning "a type of music". If someone else thinks that it's wrong, what does that show us? It only show us that Roger Woodham thinks that it's wrong. Roger Woodham does not speak for all native speakers out there.
Unfortunately for Mr Woodham, people can, and do, say and write 'a music'. The contexts in which they do so may be quite rare, but they are natural enough.
If students of mine came up with such an example, I would point out that it is rare. I would probably warn them that they are unlikely ever to come up with another convincing example of their own, and tell them that, for practical purposes it is pretty safe to take it that 'music' is almost always used uncountably. But, I would not tell them that to use 'music' countably is always automatically wrong. Because it's not.