This study addresses a long-standing mythology concerning the “Unfinished” Symphony and reviews anachronistic performance practices that prevent listeners from experiencing the work as a product of its own time. David Montgomery’s Unfinished History challenges the traditional story of Franz Schubert’s B-minor Symphony and searches for a more credible account of this great work. Written for all Schubert lovers from lay readers to musicians and musicologists, the book reviews a strangely persistent mythology concerning the symphony, continuing with the first in-depth examination of its manuscript and related documents. Details of handwriting, notation, paper, watermarks, compositional procedures, and stylistic contexts suggest a new year and country of origin for the “Unfinished” Symphony, a possible explanation for the absence of a finale in the sketches, and an alternative account of the score’s disappearance and prolonged sequestration. The author concludes with an essay on performing the work in the context of its own times. The story of the Unfinished has been based partly upon three conflicting letters written in old age by Schubert’s former secretary long after the composer’s death. A fourth document in this insupportable mythology is a photograph of a lost letter purportedly sent from Schubert to the Styrian Music Society in Graz, promising to send them a symphony. Many historians still believe the letter to be genuine, despite the fact that its signature has been traced. David Montgomery’s handwriting analysis finally identifies the real writer of this odd missive, clearing a further path to new research.