ABSTRACT: Given the horn's lengthy history, it is not surprising that many scholars have examined the evolution of the instrument from the natural horn to the modern horn and its expansive repertoire. Numerous dissertations, theses, and treatises illuminate specific elements of the horn's solo repertoire; however, no scholar has produced a comprehensive, annotated listing of these compositions. With solo repertoire representing a cornerstone of every horn student's musical education, this treatise aims to eliminate this void by evaluating and annotating one hundred of these works, and making them widely available through an online interactive database. Repertoire was individually reviewed and examined to include pieces of varying difficulty and styles in addition to the standard repertoire. The entries in this treatise include the composer's name and dates, the publication information of the examined piece, the range (in horn pitch), clef, techniques, duration, level of difficulty, the accompaniment available, and the difficulty of the piano accompaniment. A short descriptive paragraph highlights other key features of each composition. The goal of the listed information is to provide enough details about the piece so that the musician can decide if it meets his or her needs. In addition to the paper document, there is a searchable internet database component to this treatise. It serves as a quick reference tool for teachers, students, and horn enthusiasts. The internet database may be found at www.hornrep.org.