The method "Twenty Easy And Progressive Studies" by Auguste Périer for clarinet includes 20 pieces for beginners. This well-structured method is written with increasing difficulty and aims to help young musicians develop their technique and sound. Auguste Périer (1883-1947) was a French clarinetist who worked for the Opéra-Comique and served as a professor at the Paris Conservatory. He was known for his pure sound and vibrato technique.