CHICAGO — Before Game 1 of the Stanley Cup finals Wednesday night at United Center, the visiting Boston Bruins will be treated to one of the loudest and most venerable traditions in hockey: the cheers during the national anthem before a Blackhawks game.

The red carpet will be rolled out, the home patrons will stand, and Jim Cornelison will begin belting out “The Star-Spangled Banner” in his operatic tenor. But instead of respectful silence, the fans’ accompaniment will be reverential noise: clapping and cheering for a good minute and a half until the anthem is done.

This has become a familiar scene in the hockey world, but the origins are hazy. Wayne Messmer, who sang the anthem at Blackhawks games from 1980 to 1994, said he thought the seeds were planted during the Western Conference finals against the Vancouver Canucks in 1982, when fans started to cheer during the last eight bars or so of the anthem.

But the tradition seems to have truly arrived on May 9, 1985, before Game 3 of the conference finals against Wayne Gretzky’s Edmonton Oilers.