In 1955, 12-year-old Annette was discovered by Walt Disney as she performed as the Swan Queen in Swan Lake at a dance recital in Burbank. On the basis of this appearance, Disney cast her as one of the original Mouseketeers.
She was the last to be selected, and the only one picked by Walt Disney. She soon proved to be very popular. By the end of the first season of the Mickey Mouse Club, she was receiving 6,000 letters a month.
In addition to appearing in many of the Mouseketeers' sketches and dance routines, Funicello starred in a number of serials on The Mickey Mouse Club. Including Adventure in Dairyland and her own self titled serial, Walt Disney Presents: Annette.
It was in a hayride scene in the Annette serial that she performed the song that was to launch her singing career. The studio received so much fan mail about "How Will I Know My Love," written by the Sherman Brothers, that Walt Disney decided to issue it as a single, and to give Annette a recording contract.