The premiere is part of the Philadelphia Film Society's Filmadelphia at the Roxy series, which spotlights local filmmakers and their tales of the city.
On the Other Side of the Fence tells of the annual musical production that features students from both schools who pair up to prepare for their starring roles. The film follows the youngsters as they rehearse for the 30th-anniversary show in 2012 and later take the stage together in performances at both schools.
"When children are open or there is an opportunity for them to be with someone who is different in a supportive way, children become very accepting," said music therapist Andrea Green, composer, writer, and director of the musicals.
Green encouraged Nevison, an Emmy-nominated filmmaker with 30 years of credits - including programs for the Discovery Channel and Biography - to consider a film about the project when the two met several years ago.
Nevison was so taken with the idea that he began filming the following week on the first day of rehearsals. That is when he captured the awkwardness that would eventually disappear.
Germantown students began pushing their HMS partners' wheelchairs on stage, holding their microphones and communicating.
"You witness a transformation," Nevison said. "They don't need to be taught tolerance, they are experiencing it."
Nevison filmed for three months of rehearsals starting in January 2012, and then began interviews. Midway through the project, he began a Kickstarter campaign, which raised $87,000 to help finish the film.
On Tuesday, a red-carpet premiere is planned.
Later this month, Nevison and Green will travel to Estonia, where the film will have its international premiere. A community theater in Estonia is producing a musical by Green called The Return of Halley's Comet, the centerpiece of a 10-day symposium on diversity and acceptance. On the Other Side of the Fence will premiere during the conference.
The documentary later will air on Mind TV and other public television stations.
In the movie, HMS student Sean Hanlon, 16, of Conshohocken, plays a singing bear with his partner Ezra Singler of Germantown Friends. Hanlon does not speak, but uses an electronic device with voice capabilities. When it was time for his line ("Grin and bear it!"), Hanlon flipped a switch.
He has big plans for Tuesday's premiere.
"He's picked out some new clothes and got a haircut," said his mother, Kerri. "He's excited to walk the red carpet."