[Kawika]

The roofline matches up with aerial shots of Shibe Park as found on Google Images. Compare the area around the left field foul pole in your photo with Graig Kreindler's "Beast Bangs Gomez" painting. Looks the same. Only immediate clue to era are all the boaters worn by fans; that only narrows it to a couple of decades. Difficult to say what the event might be. Thin crowd, not a big game.