Among the many that resorted to him for instruction, was Lord Paisley, afterwards Earl of Abercorn; to whom Dr. Pepusch had communicated lessons in writing for his private study, with no other stipulation not to impart them to the world, than is implied in the mutual relation of teacher and scholar: which, however, it seems, was so ill understood, that in the year 1730 the substance of these lessons was by his pupil published, under the following title: A short Treatise on Harmony, containing the chief rules for composing in two, three, and four parts, dedicated to all lovers of music.