The musicians marched in their trademark scarlet-and-white uniforms. The drum line kept rhythm. The color guard twirled flags. A hundred students marched in perfect unison down a city street. Then someone yelled “Cut!” and the scene for the film Black Mass, with Johnny Depp playing Boston mobster Whitey Bulger, was done.

Aaron Goldberg, BU’s director of Athletic Bands, got the call last June from a local casting agency hoping to fill 100 uniforms for a St. Patrick’s Day parade scene. “I was worried because so many people were off campus at that point,” he says. “But within 14 hours, we had over 200 interested people, and there were almost 300 by the next day.” The band that appears in the film is actually a hybrid of about 50 band members, 30 band alumni, and 20 students from other colleges and high schools.

The group had only one rehearsal before the shoot. “We rushed through memorization of the piece, the Irish folk tune ‘The Garry Owen March,’ which was fairly simple, thankfully, so we could get outside and practice marching, because most of us had never marched with each other,” Goldberg says.

Although the real St. Patrick’s Day parade is held in South Boston, this one was shot in Lynn, which was deemed to have the long-gone grittiness of Southie in Whitey Bulger’s day.

Flutist Ava Mack (CAS’17) finds a marching band uniform that fits just right prior to shooting a scene in Black Mass.

Filming began at 6:30 a.m. “We simply marched up the street behind a float,” says BU Pep Band manager Jennifer Gough (SAR’16). “We did the same thing several times.”

Band members had practiced marching different ways so they’d be ready for whatever was needed. “Turns to the left, right, wide intervals from student to student, short intervals—we experimented with every way possible so we could be prepared for whatever the movie people asked,” Goldberg says.

What band members hadn’t anticipated, however, was that they would simply pretend to play, so the audio could capture the actors’ lines. “I cannot tell you how hard it is to get 100 students to be perfectly in time going down the street in utter silence,” Goldberg says. “The drummers had to fake play without hitting their drums.” In all, the band marched through 28 takes between 6:30 a.m. and 6:30 p.m., a 12-hour gig for which they were paid nothing, although they were given $2,500 for transportation costs and another $2,500 for dry-cleaning the uniforms.

The film, scheduled for release in September 2015, is based on the book Black Mass: Whitey Bulger, the FBI, and a Devil’s Deal, cowritten by Dick Lehr, a College of Communication journalism professor, and Gerard O’Neill (COM’70).