The cause hits close to home for the cast of the film, as Crazy Ex-Girlfriend composer and Fountains of Wayne founding member Adam Schlesinger, who wrote the movie's catchy titular song, died earlier this month of complications from the coronavirus.
All four original Oneders -- Tom Everett Scott, Johnathon Schaech, Steve Zahn and Ethan Embry -- as well as co-star Liv Tyler will be participating in the livestream, watching along with fans and commenting on the film. Embry also promised "a few other surprise guests," which could include Tom Hanks, who made his directorial debut on the film, as well as playing the band's manager, Mr. White.
Hanks, who was one of the first major celebrities to announce that he had been diagnosed with the coronavirus amid the global pandemic, shared a tribute to Schlesinger following his death on April 1.
"There would be no Playtone without Adam Schlesinger, without his That Thing You Do!" the actor wrote on Twitter. "He was a One-der. Lost him to Covid-19. Terribly sad today. Hanx."
There would be no Playtone without Adam Schlesinger, without his That Thing You Do! He was a One-der. Lost him to Covid-19. Terribly sad today. Hanx
Three of the four Oneders -- Scott, Schaech and Embry -- previously reunited in 2017 to play their eponymous hit onstage at Los Angeles' iconic Roxy Theater, which Hanks later told ET was "the coolest thing in the world."
A year earlier, ET spoke with Scott about the film's 20th anniversary, and he said that the cast has kept in contact over the years.
"We are all still pretty tight, the That Thing You Do! family," he shared at the premiere of Sister Cities. "We still go see baseball games together and we all hang out."
But, despite the fact that everyone's still so close, Scott admitted that he's not clamoring for a reboot or revival.
"Why remake something that was already great?" he wondered. "Remake something that had potential, but it wasn't really good the first time."
See more from the group's past reunion in the video below.