Varied Studies in all keys by Marcel Mule (1901-2001) is a set of thirty studies for Saxophone. Initially composed by Jakob Dont, Rodolphe Kreutzer, Jacques Mazas, Niccolò Paganini, Pierre Rode among others, these Varied Studies in all keys for all Saxophones would fit the skills of advanced-intermediate players.

Marcel Mule (1901-2001) is one of the greatest French Saxophonists, renowned worldwide for his work on the classical Saxophone repertoire. He was teaching his students how to obtain a good quality of sound and believed it was dependent on the embouchure, the emission, the mastery of vibrato and, therefore, of breathing. He wrote different methods that focus on technique, articulation and tone productions such as '18 Exercises or Studies', 'Daily Exercises after Terschack' or '30 Great Exercises or Studies after Soussmann' (in two books), among others.