Original sentence: The Piano Book,  in its fourth edition, describes how pianos work, discusses and reviews brands of pianos, tracks changes in the piano industry, describes the retail piano industry in the United States with advice on buying from piano stores.The book is written from the viewpoint of the piano technician.The book was accompanied by an annual supplement, which offered updates between major revisions
Edited sentence: Over the years, the work has been increasingly a collaborative effort, as Fine has recruited a large number of his fellow technicians to evaluate and report on the pianos that they see in the course of their work.The Piano Book,  in its fourth edition, describes how pianos work, discusses and reviews many brands of pianos, tracks changes in the piano industry worldwide, describes the retail piano industry in America with hints for the buyer on how best to deal with piano stores.The book is written from the viewpoint of the piano technician, and thus often emphasizes aspects of piano quality that make it hard or easy for the technician to keep the instrument in tune and in good working order.The book was accompanied by an annual Supplement, which offered updates to tide the book over between major revisions