"The Roaring Trumpet" is a fantasy novella by American writers L. Sprague de Camp and Fletcher Pratt. The initial story in their Harold Shea series, it was first published in the May 1940 issue of the fantasy pulp magazine Unknown. It first appeared in book form, together with its sequel, "The Mathematics of Magic", in the collection The Incomplete Enchanter, issued in hardcover by Henry Holt and Company in 1941, and in paperback by Pyramid Books in 1960. It has since been reprinted in various collections by numerous other publishers, including The Compleat Enchanter (1975), The Incompleat Enchanter (1979), The Complete Compleat Enchanter (1989), and The Mathematics of Magic: The Enchanter Stories of L. Sprague de Camp and Fletcher Pratt (2007). It has been translated into Dutch and Italia