It was music.
Here's what we know about Ryne Sandberg:
Sandberg finally broke, but it wasn't due to the Phillies' poor play, their lack of hits with runners in scoring position, their baseball-worst 153 runs scored, their almost baseball-worst .293 OBP, or his inability to figure out how a bullpen works and what his role is in using it. It was music.
As we know by now, the Nationals have matured from giggling toddlers to smirking teenagers who think they are going to live forever. Instead of trying to keep Phillies fans out of their park with computer trickery or signing former Phillies and getting them to say the Nationals are better, they have resorted to more subtle pranks.