Choose the sentence in this excerpt that identifies the most important function of pitch-correction software to its inventor, Harold Hildebrand.
After many years of successfully locating oil deposits, Hildebrand left the oil business. He combined his engineering skills with his first love and started a music software company. Then, in response to a good-natured challenge from a friend to invent a device to help her sing in tune, Hildebrand realized that auto-correlation could be useful to sound technicians in the music industry. He saw a way to save on the time and effort technicians spend in recording studios producing pitch-perfect vocal tracks.