Unfinished Music draws its inspiration from the riddling aphorism by Walter Benjamin that serves as its epigraph: "the work is the death mask of its conception." The work in its finished, perfected state conceals the enlivening process engaged in its creation. Author Richard Kramer moves from some explosive ideas of J. G. Hamann, on the place of language at the seat of thought, to explore the no less radical music of Carl Philipp Emanuel Bach, whose bold idiosyncrasies, like Hamann's, disrupted the discourse of Enlightenment aesthetics. In several chapters on the late music of...