The purpose of this document is to assist in both the performer’s preparation and performance of Áskell Másson’s Marimba Concerto for orchestra through an understanding of the thematic material, which the work is founded. This author believes that an understanding of the formal structure and thematic development of the concerto is essential to realizing a musical performance. Background information on Áskell Másson, including a brief biography and discussion of compositional style and output, are provided to further enhance the understanding and performance of the concerto. Also included is a compilation of interviews with the composer, offering insight into Másson’s past, current and future accounts, which is meaningful to the composition and performance of the work itself. Performance suggestions are provided by the author as a medium of interpretation and are related to the thematic structure of the work. As part of this document and for purposes of the accompanying recital, the author has generated a piano reduction of the orchestral score with collaboration from the composer. The piano reduction will also enhance the possibilities of future performances, making it increasingly accessible. The piano reduction of the Marimba Concerto will be published through Editions Bim, also the publisher for the concerto. It is the author’s belief that this document will provide a basis of study for future performers of Áskell Másson’s Marimba Concerto.