The odd thing about this is that no Canadian teams were playing. Buffalo is the only team that plays both national anthems, regardless of who's playing. In the game, the Boston Bruins went on to defeat the Buffalo Sabres 2-1 in overtime.

Source: New York Times

As Cami Clune sang the Canadian national anthem before a National Hockey League playoff game in Buffalo on Tuesday night, she faced a singer’s nightmare: Her microphone started cutting out.

So the Buffalo Sabres hockey fans at KeyBank Center stepped in. As Ms. Clune’s mic malfunctioned, they belted the lyrics to “O Canada” along with her.

“Well that was interesting!!” Ms. Clune wrote on social media afterward. “Thank you all for singing along with me. We have the best fans ever!”

At most N.H.L. arenas in the United States, “O Canada” is performed only when the visiting team is Canadian. But in Buffalo, which borders Ontario Province and has close economic ties with Canada, the Canadian anthem is sung before each game.

The moment of amity presented a contrast to ongoing U.S.-Canada tensions over President Trump’s tariffs and threats to Canada’s sovereignty.