CHICAGO — A new tune was introduced to the soundtrack of Wrigley Field on Saturday.

In a ballpark known for its seventh inning stretch and victory song, “Go Cubs Go,” Ohio State football fans echoed a new sound.

“O-H”

From the concession stand lines on the concourse to the packed streets of Wrigleyville, the popular response could be heard.

“I-O”

With Northwestern’s Ryan Field under construction, the Wildcats took homecoming to the city’s north side ballpark.

It provided a backdrop for an outpouring of Ohio State fans to take over one of the nation’s biggest cities and one of MLB’s oldest ballparks.

Scarlet and gray fills Wrigleyville

Wrigley Field’s centerfield hand-controlled scoreboard has been updated to reflect the sport taking place Saturday.

Its out of town scores are labeled to represent quarters instead of innings, with the Big Ten’s Week 12 slate displayed.

Behind the scoreboard, at the intersection of Sheffield Ave. and Waveland Ave., the popular bar Murphy’s Bleachers filled up early for an 11 a.m. local kickoff.

Its patio was flooded with scarlet and gray.

However, despite a small contingent of Northwestern fans, Ohio State fans were trolled just a couple buildings down from Murphy’s Bleachers.

A fan donning an Oregon shirt stood in a window — similar to a mannequin at a Michigan Ave. shop.

He had with him a sign that read, “Ohio St has not beat Michigan in 1,813 days.”

Signs of baseball remain at Wrigley Field

The infield was covered with turf, ensuring no play takes place atop dirt. However, small patches of the warning track provide a reminder that Wrigley Field is, still, a baseball stadium.

Fans in right field also had an opportunity to experience a baseball-centric moment during warm-ups.

The Allstate-sponsored netting that stops kicks from going into stands isn’t in place in the east end zone.

As kickers practiced pregame, field goals going that direction made it into the right field bleachers like a home run.

Ohio State coach Ryan Day said, ultimately, the game is about 100 yards of grass and not what surrounds it.

But for these in the stands, Saturday provided an experience unlike many in college football.