"Hopefully I can keep it together," he said Saturday. "You know it's going to be emotional, but I don't know how deep."
In his final game after 19 years as the anthem singer, the St. Louis Blues have a chance to clinch the first championship in their 52-year history. They lead the Boston Bruins 3-2 in the best-of-7 series.
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The 64-year-old, who has multiple sclerosis and is retiring, will be like the players in a sense.
"I'm leaving every note I've got on the ice," he said.
Glenn has been an institution at Blues games, belting out a powerful, relatively straightforward version of "The Star-Spangled Banner." When he ends the anthem with "brave," the fans replace the word with "Blues!"
"You can see the emotional lift that the crowd gets when he walks out there," said defenseman Alex Pietrangelo, the Blues captain, who has played in St. Louis since 2008. "These are the people that have been in the organization, that have been here for a long time, waiting their turn. It's guys like him … that you want to make sure you give a good effort for."
Glenn loves this team.
"I bleed blue," he said. "I mean, I'm a huge Blues fan, and it runs in the family."
When he first started singing at Blues games, he brought his daughter, Elizabeth, who was 8 or 9 at the time.
"I said, 'We're going to a hockey game,'" he said. "She said, 'I don't like hockey, daddy.' I said, 'Have you ever seen hockey?' She goes, 'No. I see it on TV, and I turn away.' She saw her first game, and when she turned 19, she ended up being a Blue Crew girl. She fell in love with it immediately."