Hmmm. So rather than confer deference upon an "authority", you propose there can be no correct answer. Interesting. Hardly novel, but interesting nonetheless. I submit there is a correct answer (sometimes more than one). But there is at least a correct answer. If what you propose were true, you could call a donkey a bull, I could call a bull a chicken, and the candlestick maker could call the chicken a donkey...and we would all be correct. But this just ain't so.
How do you get the idea that there is no correct answer from what I wrote?
There is a correct answer to the question, "what is 'rock' music?", but it is not what you want it to be. To reiterate what I have said before, "rock" music is a broad category, not a narrow one, and it is full of "sub-genres" (see the links I provided earlier). Madonna, regardless of her merit or lack thereof as a musician, person, or thing, performs or has performed music that fits under that broad category that is called "rock music".
Now, you, as well as a few other people, wish to misuse the term "rock" music by insisting that it has a more narrow meaning than is commonly given to the expression. (Or, to be more precise, to misuse it by insisting that it does not have this broad meaning that I have mentioned repeatedly; many words have more than one meaning—just consult any standard dictionary, and you will see that most words have several different and slightly different definitions, and all are correct usages.) You can insist that words do not have the meaning that they have, and invent your own, but you will not be properly speaking English when you do such a thing. You can rant and rave all you want, but if you are interested in what words mean, I strongly suggest consulting dictionaries and other such reference materials. To simply say, "I KNOW WHAT IT MEANS!", shows no knowledge of anything whatsoever. It simply shows a stubbornness and an unwillingness to see reason. Language is essentially something communal, and words are not given their meanings from one person wanting them to have a particular meaning. But, to reiterate, there is nothing stopping you from misusing words. Just don't expect the rest of us to go along with your misuse of words.
