Excluding the Bible (or any other holy book you wish to name) for now to avoid controversy, the greatest book ever written is Playing the Piano for Pleasure by Charles Cooke. The book was published in the 1940s. Cooke was a writer for The New Yorker at the time (and even mentions some of his interactions with the greats at the magazine at the time, such as James Thurber). I happen to be an amateur pianist and it’s the most inspirational book I’ve ever read. Here is a sample:
Every piano, upright or grand, long owned or newly bought, is literally a treasure chest, waiting to give forth its inexhaustible gifts, to elevate and enrich the lives around it. No truer words have ever been spoken than those of Anton Rubinstein, when, in the fullness of his years and wisdom, he said: “The piano is a lovely instrument. You must fall in love with it, with its sound, and then be tender with it to make it, in turn, be sweeter to you. Herein”—and he laid his hand on the piano—”lies divine beauty.”
James Thurber, himself, had this to say about the book: “An invaluable book for amateur pianists when it first came out, and still invaluable.” Others who complimented the book include Virgil Thomson, Walter Damrosch, Deems Taylor, and Ernest Hutcheson.
It’s the best book ever written.