The organ has been called the "king of instruments," and when it's used in an orchestral work, the challenge is to keep it from overpowering everything else -- unless, of course, that's the point, as in the opening moments of Richard Strauss's Festival Prelude for Organ and Orchestra.
It's a challenge that's been faced and met by a wide range of composers, as we'll explore in this hour, with works by Handel, Haydn, Liszt, Saint-Saens, and Copland, among others.