While organ music had appeared at hockey rinks in the 1930s, it first blared through a ballpark April 26, 1941. Organist Ray Nelson played “classic and soulful compositions‘ before the Cubs faced the Cardinals at Wrigley Field. However, he had to stop before the game began because he was playing copyrighted songs that could have been picked up by radio broadcasts.
However, the ballpark organ quickly caught on; The following season, the Brooklyn Dodgers hired a permanent organist, and their popularity increased in the mid-20th century. Nowadays they are commonplace.
Curiously, the Cubs removed Nelson’s organ from the stands during a road trip shortly after its release – the copyright liability was just too much for them – and organ music did not return to Wrigley until 1967.