https://www.wxyz.com/sports/bills-to-honor-their-northern-fans-by-having-o-canada-performed-at-home-opener-against-lions
...This isn’t the first time the Bills have played both anthems during games at Orchard Park. The Bills under late owner Ralph Wilson once hosted an annual Canadian fan appreciation game, which was scheduled near Canadian Thanksgiving, which falls on the second Monday of October.
The featured outings were discontinued about 20 years ago, and before the team played a series of annual regular-season games in Toronto over a six-year span, ending in 2013.
The NHL's Buffalo Sabres have had both the Canadian and American anthems performed before each game no matter the opponent in a tradition that began with their inception in 1970. The Bills and Sabres are now both owned by Terry Pegula.
During the NHL playoffs this spring, hockey fans memorably chimed in en masse by singing “O Canada” when anthem singer Cami Clune's microphone stopped working...