According to the New York Daily News, the Mets were the victim of an internet-organized prank. When asked to vote for the new 8th Inning song at Shea Stadium, "fans" apparently voted for the ubiquitous "Never Gonna Give You Up" by white chocolate himself, Rick Astley.
I for one am appalled and shocked of the intentions of these people. The Non-American League baseball team in New York deserved far worse. But congrats go out to all who participated in making the Mets fans as unhappy as can be.
Audio is a little low but picks up at the end.