This is a classic clarinet piece written specifically for Bb clarinet and piano, suitable for advanced students to professionals.
It's four sections, Allegretto, Allegro Animato, Lento, and Molto Allegro. The main theme is stated and developed in the first part, and it's re-stated later at the end. The animato section is more playful and lively, while the Lento is very dark and somber. Finally, the Molto Allegro is the most challenging section, very fast and strong.
Overall this is one of the finest clarinet sonatas, giving the listener a great range of moods and challenging the player's technique to the fullest. This is the Elkan-Vogel Edition, a new American edition.