Brian Evans insists he’s never been a get-the-last-laugh kind of guy.

“No anger in me, no sir,” he says solemnly. But just before the first inning of a recent Red Sox home game — against the New York Yankees, no less — the in your face! ear-to-ear grin was unmistakable, as Evans, in the bleachers surrounded by friends, heard his own voice on the loudspeakerscrooning “At Fenway,” his tribute tune to Fenway Park in its 100th year.

The catchy melody that Frank Sinatra might have sang if he’d been a Sox fan, was offered by Evans to the Red Sox last fall. It was lost in the quagmire of administrative vetting and paperwork for months, but has been blasted by stadium workers during Red Sox home games for about a month now.

But in spite of its long journey from studio to stereo, when “At Fenway” got to the plate, it hit in a big way.

The Sox love it. “It seems really fitting as we celebrate Fenway Park’s centennial,” says Zineb Curran, Red Sox director of corporate communications. “We appreciate the different ways all our fans try to honor the club. So it’s a great year for the song.”

The National Baseball Hall of Fame has added it to its library. And Major League Baseball licensed the song for game use — a first for the league.

“That part of it has been surreal,” Evans says. “Them making it an ‘official’ song is really very cool, and c’mon, it would be for any Red Sox fan. I’d say it’s one of the best things that’s ever happened for my career.”

That career? If you haven’t guessed: big band singer. Think Sinatra, Tommy Dorsey, Benny Goodman, Duke Ellington. And if you get those voices, then you get the music that the 42-year-oldBrian Evans makes.