This chapter reconstructs the musical genesis and performance history of the A-Major Symphony. Mendelssohn accepted the Philharmonic Society's commission in a letter dated 28 November 1832, but his initial compositional activity does not seem to have included work on the A-Major Symphony. To venture into the compositional history of the "Italian" Symphony is to open a Pandora's box of failed expectations, false leads, and cryptic references. In MN 28 Mendelssohn departed from his normal tendency toward compression in order to include a reprise of the second subject between the development and the return of the tarantella. In Mendelssohn's concern for structural cohesiveness in the A-Major Symphony lies the key to understanding the significance of the revisions he introduced in MN 28. "Aber eben dieser Zweifel": this phrase illuminates not only the nature but also the source of Mendelssohn's frustrations with the AMajor Symphony.