Megan Quamme just graduated from the University of Minnesota with a biology degree. But her plans to become a physician assistant one day are on hold while she spends the summer dancing like a movie star and spinning flags across the football fields of America.

Quamme, 21, performs each night in a different city as part of the color guard for Phantom Regiment, a drum and bugle corps from Rockford, Ill. She’ll be among the more than 2,000 musicians and performers who will descend Saturday on TCF Bank Stadium to compete in DCI Minnesota, one of the big stops on Drum Corps International’s summer tour, which returns to Minneapolis after a two-year absence.

It’s one of the nation’s largest drum and bugle corps competitions, featuring 10 World Class finalists from the 2014 DCI World Championships plus 10 other corps from the United States and Canada.

For Quamme and dozens of other Twin Citians who perform and teach with the corps on DCI’s eight-week national tour, Saturday’s show isn’t just another contest. It’s the closest they’ll come to home in an alternate summer world driven by daylong rehearsals, evening shows and all-night bus journeys.

This isn’t just a marching band show. Drum corps programs are much more dynamic, a fast-paced musical spectacle powered by up to 150 elite brass musicians, percussionists and color guard members, who provide the visual oomph through dance, movement and work with flags, rifles and props. The latter is where you’ll find Quamme, virtually visiting Paris every night as part of Rockford, Ill.-based Phantom’s “City of Light” show, whose music includes Gershwin’s “An American in Paris.”

“My role in the show as part of the color guard is to be an American who just landed in Paris and has 24 hours to explore all the landmarks of the city,” she said. “Our image this year as a color guard is designed a lot off of Audrey Hepburn in ‘Funny Face.’ ”

Bryan DeHerder, 21, a graduate of Rosemount High School who’s studying mechanical engineering at Iowa State University, faces similar artistic challenges as a trumpet player with the all-male Madison Scouts of Madison, Wis. Part of his drive in performing their show, “78th and Madison,” a tribute to the MGM musicals of Gene Kelly, is “to show the judges and the fans that the Scouts are back to play hard ball, especially coming off a year like last year where we struggled a lot.”

Run as a nonprofit activity, the DCI tour works like this: Each night, the corps perform their 10- to 12-minute field shows for an audience, which numbers hundreds of people on a typical night and thousands for a regional competition like DCI Minnesota. Judges evaluate the show based on musical and visual execution, quality of program and general effect — how well what’s happening on the field connects with the audience. The corps scoring closest to 100 wins, with awards given for categories like top brass, percussion and color guard.

This happens every summer night in a new town until the first full week of August, when the corps all converge in Indianapolis for the DCI World Championships. Through several days of competition, the field is winnowed until a new champ is crowned on Aug. 8.

Quamme will return to real life and a future health career after the DCI World Championships. Until then, she said, she’s having a great summer.

“I do elite ‘marching band’ all day long for three months,” she said. “It’s the hardest and most rewarding thing I have done and will probably ever do.”