On August 13, 1951 — Every one who shows up with a musical instrument is admitted free to Ebbets Field. 2,426 fans take advantage of the offer, including one with a piano. The Dodgers have a motive in countering the local musicians’ union which wants to silence the non-union Sym-Phoney. The Dodgers outplay the Braves, 7 – 6, as Gil Hodges belts a three-run homer in the 8th, following an intentional walk to Roy Campanella, who had homered earlier.

Source:
Baseball Reference August 13
National Pastime
Retro Sheet
Hall of Fame
SABR Games Project
Replay The Game