Complex sentence: The first, in D minor, was an early work, now lost, written in the early 1860s at the request of his teacher, Carl Reinecke, the third quartet, in F major, remained incomplete at the composer's death.
Split into simpler sentences: The first, in D minor, was an early work, now lost, written in the early 1860s at the request of his teacher, Carl Reinecke. The third quartet, in F major, remained incomplete at the composer's death.