Music does not have a purpose. A composer may.

Purpose is implied by music's universal significance to human culture & the individuals thereof for whom it most certainly does have a purpose; language, art, religion likewise (though there are significant overlaps).

Unrest does not create privilege of the few. Rather, it tends to disturb it.

The unrest is both an inevitability of privilege and means to further repression, both to justify it and disempower the revolutionary potential of the proletariat whilst given them the illusion of power. Unrest is a carefully controlled pressure valve that simultaneously placates and terrifies (and by implication pacifies) civilian populations who crave social stability. Thus do I say requisite, in the same sense that poverty is a requisite of wealth in a functionalist society.

"Muggle", a person without magical abilities in J. K. Rowling's Harry Potter fantasy books and films. The term was later adopted by various subcultures to identify those outside their group or lacking in a skill.

That's the one! In certain folk circles the term 'muggle' has come to used to refer to non-folkies.