Years before he died last May at age 62, the legendary poet, novelist, and musician Gil Scott-Heron had been working on a memoir. Canongate Books, his publisher in Britain, announced plans to publish the book nearly a decade ago, and on the Canongate website there is a spectral recording from the early 1990s of Scott-Heron reading a chapter from an early draft of the manuscript. Now, the publication of The Last Holiday

…