The appreciation of music is also subjective to a great degree, but it can be heightened through increased knowledge and understanding of the techniques behind it. For example, even a person who believes that he is tone-deaf can be taught to distinguish between performers whose intonation is flawless and those who display tendencies toward sharpness or flatness of pitch. These variations in pitch can be demonstrated through mechanical means, so that one need not even depend on a less-than-perfect sense of pitch perception. In the same way, the listener can also be taught to identify idea patterns and structural developments in improvised jazz choruses as well as the differences between conventional and unconventional harmonies and chord progressions.
True, some untrained listeners can perceive these subtleties on an intuitive level, but the majority cannot, and they're the ones who would best benefit from the experience of a qualified critic, if only to be pointed in the right direction. Curiously, though, for every novice who has the humility to admit that he does not already know everything there is to know about jazz, there are dozens more whose egos get in the way of their own learning process. They simply refuse to acknowledge the fact that others may be able to teach them something. These are the ones who shy away from reading anything more analytical than liner notes. And these are also the ones who are the first to write angry letters to the editor. Every time some self-ordained arbiter of taste delivers some scathing attack on a cherished idol, these easily outraged sycophants rush into print demanding his summary execution. They simply cannot tolerate opinions that clash with their own, even when the critic takes special care to support his commentary with concrete examples and illustrations.
Precisely because it dares to flout conventional thinking and refuses to pay lip service to sacred icons, criticism is the least respected and most reviled genre of literature extant. But if most people knew as much about their favorite art forms as the critics did, there would be no need for them to serve as interpreters, elucidators, molders of public opinion. Every person would then be his own most informed critic, and there would no longer be anyone left to write angry letters to editors. Just think how boring that would be!