When listening to music, there is usually some expectation on the part of the listener that the piece will conclude in some way. This is particularly true of tonal music, which uses specific constructs as means of closure. Closure in post-tonal music is not nearly as specific, and listeners' expectations therefore are vary in their approaches to closure. To discount the possibility of closure, or to rely largely upon tonal constructs, is to place limitations on how we think of post-tonal music, and our further understanding could be hampered without exploring the unique ways closure is achieved in this music. Consequently, this thesis focuses exclusively on closure. This thesis focuses on identifying four types of closure and describes how they work in post-tonal music: ternary, mirror, set, and pattern closure. As Arnold Schoenberg is one of the innovators of post-tonal composition, the examples focus largely on his works, particularly those composed with the twelve-tone technique. After presenting moments of closure through tonal and post-tonal music, I focus on Schoenberg's Concerto for Violin to demonstrate how these closing gestures interact to create closure.