Scholars and performers have long wondered when and why Beethoven composed an alternative ending to his string quartet, Opus 130. The original, the Grosse Fuge, was an immense and heavy multi-sectioned fugal finale; the second was a much shorter and lighter hybrid sonata-rondo form finale. The second finale was the last substantial piece Beethoven composed and is reminiscent of earlier dance-like 2/4 Allegro finales composed by Beethoven, likely influenced by Haydn. This style is seemingly incongruous with our current understanding of Beethoven’s late style, centered around foreign harmonies and forms, with expansive thematic material. While research on this topic has been extensive, including studies in biography, source material, reception history, and harmonic and formal analysis, it has not led to a fully adequate understanding of this second finale. My study aims to provide a fresh understanding of this movement through the examination and evaluation of the later stages of its composition. The major sections of revision found in the composing score, Berlin, Deutsche Staatsbibliothek, MS Autograph 19c, and the autograph fair copy, Berlin, Deutsche Staatsbibliothek, MS Grasnick 10, are closely studied here for the first time. In order to highlight important steps in the creative process, I have selected four heavily revised areas from each of the sonata-form sections of this movement as shown in both manuscripts. My interpretation of these revisions is based on comparison to parallel sections in both manuscripts and the final version, as shown in transcriptions of these passages from the sketches along with accompanying images of the original pages. For each of these sections, I attempt to suggest the order in which Beethoven made his revisions, and I discuss their formal, thematic and harmonic implications. As a whole, these revisions reveal Beethoven’s concern for economical treatment of thematic material, especially motives from theme 1a, and a concern for playing upon the harmonic and formal expectations of his audience. The voicing of theme 2a in the exposition and recapitulation, and the voicing and texture of theme 1a in the development, the false and authentic recapitulations and the coda are analyzed in terms of momentum, sectional balance, texture, and dramatic tension. I suggest that further study of these sketches and related primary source material might help to revise our notion of Beethoven’s late style.