Schubert

Schubert was a musician who created over 600 works of music, but died before he could finish his eighth symphony.

Biography
Schubert presumably dedicated his life to his music, as he created over half a dozen hundred works. His music was famous enough for The Mechanic to greatly enjoy it as a child. One day, an extremely smart man known as Devoe studied all of Schubert's works and pieced together what would have been the ending to his eighth symphony

Trivia

 * Franz Schubert was a renowned Austrian composer who composed over 600 works, and indeed never completed his eighth symphony.