Soon after Harry joined the Chicago White Sox in 1976, owner Bill Veeck noticed him humming along as organist Nancy Faust played the song. Veeck asked Harry to sing the song into the microphone for all the fans to hear. Harry wasn’t interested. Unbeknownst to Harry, Veeck had already taped him singing during commercial breaks. Veeck gave Harry the choice of singing live or playing the recording. Harry chose live.
When Harry left the White Sox and joined the Cubs in 1982, the tradition went with him, and thanks to cable superstation WGN, the whole country got to experience the 7th inning stretch with Harry.
Since his passing, the Cubs continue to honor Harry by inviting guest celebrities, local and national, to lead the singing Harry-style. The use of "guest conductors" at Wrigley Field continues to this day and features Harry’s well-known caricature above the broadcast booth. Watch the video below to see newspapers chronicling Harry’s rise to fame and, at the end, sing along to the 7th Inning Stretch with him.