The Answer:

The Vocal Group Hall of Fame, located in Sharon, Pa., was founded in 1997 "to honor the Greatest Vocal Groups of The World in every genre of music." In order to be considered for induction, nominees must have at least a 20-year history in the music industry, a hit record or significant vocal contribution, and a minimum of three part harmony.

We have a full list of Vocal Group Hall of Fame inductees.

—The Editors