You will be given a definition of a task first, then some input of the task.
Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Prelude and Fugue in A minor, BWV 543 is a piece of organ music written by Johann Sebastian Bach sometime around his years as court organist to the Duke of Saxe-Weimar (1708--1717).
Output:
What type of instrument is Prelude and Fugue in A minor, BWV 543 designed for?