Hans Haug (1900-1967) was a prominent composer and conductor in central Europe who collaborated with many concert artists, theater companies, dance troupes, and music festivals. His contribution to the literature for guitar is exemplary, with extensive usage of the guitar in orchestral works, as well as contributing to the literature for solo guitar, and most significantly, to chamber music featuring the guitar. Collaboration with prominent musicians including Andres Segovia, Konrad Ragossnig, Jose de Azpiazu, and Louise Walker led to Haug's working knowledge of the instrument, as well as the creation of his chamber works featuring the guitar in the last ten years of his life. This book traces the evolutionary approach to melody, harmony, and rhythm in both his solo works for guitar, as well as the published concert works for flute, oboe, and piano to establish "sylistic" guidelines for his chamber works featuring the guitar. His Harmony of Gravitation theory is outlined through interviews with former students of Haug, including composer/conductor Michel Rochat and guitarist Konrad Ragossnig. The book also serves as a performance guide for guitarists eager to perform Haug's works.