I know you have pulled this kind of weed many times before but kindly try attempting to pull one for me if you will.

What kind of music do you like?

What kinds of music do you like?

There are classical, baroque, modern, jazz, hip hop, slow, and fast music. Any many more kinds.
Those 2 questions are actually about the same. But you'll probably use the 2nd question if for example the person you are talking to says this:

A: I like many kinds of music.

B: Oh, so what kinds of music do you like?

Generally, you would use singular questions if you believe the answer is singular and plural if the answer is many things. If you don't know how the listener would answer then it doesn't matter which one you use.
"what kind of music do you like?" confines the answer to just 1 genre - or at least, any one of a more generalized form: loud, fast, slow, noisy or soft. but only ONE.

but then, isn't the word "music" already plural because it encompasses ALL genres? so in this case, the answer may also exceed just one classification or genre.

"what kinds of music do you like?" permits the answer to enumerate more than just 1 genre or classification.

in this case, perhaps the context in which the word "music" is used describes it as singular. which allows the word "kinds" to be used in front of it.

am i making sense, anyone?