In the middle of the 19th century a crisis in the development of symphonic music occurred. How should pieces interact with the masterworks from the early part of the century strongly identified with Beethoven? Should composers conform to the conventional norms of Formenlehre, or was each piece to seize its own form? Perhaps the most important response to the crisis is to be found in Franz Liszts body of 13 symphonic poems and 2 programmatic symphonies, and also in Richard Wagners domestic tone poem, the Siegfried Idyll. The triumphs and failures of Liszts and Wagners experiments in a new type of symphonic music ultimately served as models to the highly individualized forms and compositions of early modernists, including Richard Strausss tone poems and Gustav Mahler and Jean Sibeliuss symphonies. Works of this later generation have recently been examined by James Hepokoski and Warren Darcy, who have peered into how these works interact with processes of sonata deformation, rotational form, and interactions with their notion of sonata theory. The purpose of this paper will be to devise a formal analysis of the Siegfried Idyll, which attempts to link the pieces formal aspects with the symphonic poem compositional style and the common deformational options of the later 19th century.