Stage or street corner, Mark Nicholson doesn’t care where he plays his trumpet. As long as there are people to listen.

Every day on the well-worn steps of the Philadelphia Museum of Art, Philadelphians and tourists alike take their turns pretending to be Rocky. But if you make the climb on the right afternoon, Mark Nicholson can make you feel as if you really are the champ.

Off to the side, Nicholson sets up his speakers and displays a championship belt that holds muscled portraits of Balboa, Creed, Drago and Lang. Then, he pulls out one of the 10 trumpets he owns, and starts to play. “Gonna Fly Now” and “Eye of the Tiger” give some runners an extra boost, but mostly just make families smile when they recognize the songs.

Nicholson, 47, is a professional musician; he plays the trumpet with bands and in other gigs across the Philadelphia area. But he loves just as much to set up in public and playing for whoever may be walking by, such as at the Art Museum steps, or on a South Philly street corner before an Eagles game.

“I would play if I got negative-five dollars, if I got a million dollars. It’s just a part of me,” he said.

“I believe this is who I am. I believe this is my purpose.”

Nicholson was born in Detroit, and grew up more passionate about sports than he was about music.

He learned how to play the trumpet from his father, who was also his high school band teacher. Even though Nicholson wasn’t particularly dedicated to music, he kept playing to please his father.

“He always used to tell me, you need to learn your instrument,” he said.

When he went off to college at Michigan State, Nicholson dreamed of walking onto the school’s basketball team. He tried out and didn’t make it. But his father encouraged him to audition for the school’s band, and Nicholson got in, even though he saw music as little more than a hobby at that point.

His junior year, Nicholson was depressed. One of his friends had died, and basketball no longer excited him or seemed like a real possibility. But then one night during the summer of 1997, his life changed.

He woke up in the middle of the night to see the Spike Lee film, Mo’ Better Blues on his television. Nicholson saw Denzel Washington, Wesley Snipe and Lee starring in the film about a jazz trumpeter, and was never the same.

“It was like an epiphany. It was a calling for me to immediately focus strongly on being a great musician and following music,” he said.

The next day, Nicholson went to a record store in downtown Lansing and bought the soundtrack to the movie. He started going out to Red Cedar River, which ran through campus to practice his trumpet, so much that he was nicknamed “Music Man” and was featured in a student newspaper article.

He enlisted in the Air Force after college, and played in service member bands. After his four years of service, he played anywhere he could — churches, schools, funerals, weddings, middle school parties. It didn’t matter.

“It was like a movie, and man, I fell in love. When I started loving it, I already had the basic skills. It just went to another level,” he said.

Even before Nicholson moved to Philadelphia in 2008, the city’s culture drew him here.

He heard Jill Scott’s debut album in 2000, and felt a powerful sense of inspiration. On the insert of the CD, Scott included a picture of her North Philly neighborhood off Lehigh Avenue, and even though he was still living in Michigan at the time, he just had to go there.

“I had never been in North Philly before, and I said, ‘She’s gonna come out one of those rowhouses and I’m gonna meet her,’” he said.

Nicholson drove down and set up with his trumpet right on the street corner, and started playing Scott’s music. She never came out, but her neighbors did.

“I remember one guy said to me, ‘I don’t know what you’re doing, but you’re doing it.’ And he gave me $5,” Nicholson said. “I thought that was so cool.”

They did meet eventually at an autograph signing years later, but Nicholson believes that they truly connected when Scott once reposted a video on her social media accounts of him playing her music outside of her concert at the Met.

“That’s something that made me proud,” he said.

Once Nicholson had fully moved to the city, he was playing trumpet on a South Philly street corner when a few photographers approached him, asking whether they could take his picture, promising that he would see it some day.

“I didn’t [think] much of it. Maybe about a year later, I was driving [on] Broad, near Brown Street, and I looked up and said, ‘oh, my God,’” he said.

He saw his face on a large mural, playing the trumpet for anyone driving down Broad Street. It’s still there today, not too far away from the Met.

“I just looked at the face and the lips and how I hold [the trumpet] with the pinky. I said, ‘oh, my God, it’s me.’ And I told my family, they came to visit and I showed them that and they said, ‘yep, that’s you, Mark.’”

Nicholson, who currently lives in the Lancaster area, posts now and then on his Instagram account, @datmusicman, mostly of the sharp outfits that match his different colored trumpets.

He made sure to post a recording of the Sunday Night Football promo video he was included in for the Eagles game against the Miami Dolphins last season, where he played Rocky music with a metallic green trumpet, while wearing his custom “Music Man” Eagles jersey and a Gritty hat.

He knows that his music career isn’t the most conventional one, but neither was his path to this point. Nicholson is having fun being his own Philly subculture, and it makes him happy to see people enjoying his talent.

At his Art Museum setup, Nicholson has a sheet of paper with a QR code inside a picture frame for listeners to send tips via Venmo. It stands inside of his trumpet case, behind the Rocky themed championship belt, blocked by Nicholson’s large speakers to one side and his body as he stands in front of it to play. You would have a hard time seeing it unless you were right next to him.