I liked Schnabel's Interpretation of Piano Music but classical pianists will get the most out of it. In this book Konrad Wolff details Artur Schnabel's interpretive style which is subjective but well thought out. The musical examples are from Bach to Brahms with a Debussy example being an exception. This was Schnabel's main teaching and performance repertoire. Overall this book is a good reference for a musician looking for solutions in musicality or alternate ways of thinking about them.