Description: Niels Viggo Bentzon (1919-2000) is the most significant composer in the post-Nielsen period of Danish piano music. Bentzon's Third Piano Sonata, Op.44 was composed in 1946 and is considered by Mark L. Lehmann to be one of the great piano sonatas of the twentieth century. Not only does this sonata reflect Hindemith's ideas, but it also reveals Bentzon's unique style that successively empowers his innovative features. By applying Hindemith's theory, this study offers a way of understanding this piece and demonstrates the relevance of Hindemith's theory as a tool for analyzing the sonata. Chapter 1 presents the significance of the study, the state of research, the purpose of the study, and method. Chapter 2 provides a theoretical analysis of Bentzon's Third Piano Sonata, Op. 44. With a discussion of each movement, this analytical chapter traces Hindemith's influences: Bentzon organizes the four movements with a clear formal structure, a mediant relationship between the first movement and the rest of the movements, and a motivic coherence of each movement. Also, this chapter demonstrates how Bentzon follows Hindemith's way of chord construction and harmonic progression. This chapter provides insight into Bentzon's original style that facilitates an understanding of the tonal organization of each ...