The Von Trapps found out last spring that "The Sound of Music," the movie based on their real-life family that fled Austria to escape the Nazis during World War II, was being remade after almost 50 years into a live television event.
Myles von Trapp Derbyshire is the great grandson of Maria von Trapp, the matriarch of the family, who was played by Oscar-winner Julie Andrews in the 1965 film.
Even though Von Trapp Derbyshire told ABC News he doesn't understand why anyone would try to remake this classic film, his biggest problem is the casting of Grammy-winner Carrie Underwood for tonight's NBC special.
"It's just upsetting that this could potentially be the final broadcast of our story," he said. "And although her voice is amazing, she doesn't have acting experience…. It's just the overall image, she's a country star, she won 'American Idol,' she's very public in kind of a tabloid way."
The 28-year-old New Yorker is very proud of his family's legacy and said, "Now we have this very glossy, tabloid figure playing this role."
He explained that Andrews and also Mary Martin, who originally played Maria von Trapp on Broadway in the 1950s, were both well-respected actresses.
"[Our family has] had the conversations of who could play this role better and it was Anne Hathaway, for example," he said. "Here's someone who just won an Oscar for a similar situation [in Les Miserables]. She was able to act and sing."
Myles's aunt Francoise von Trapp even went as far as to blog, "Carrie Underwood as Maria? Seriously?" when she heard of the casting for tonight's remake.
Underwood, 30, recently told Entertainment Weekly that fans have gone as far as to send her hate tweets for taking on the role. She added that the acting part is her biggest apprehension of the live musical.
"I think so many people out there still don't understand what we're doing and, therefore, they do have this incredible ownership over the movie, like 'You can't remake that movie!' I get hate tweets and stuff like that and like, 'You're not Julie Andrews!'" she told EW. "I know I'm not - nobody is, and I would never pretend that I was. I know my place, you know?"
A request for comment from Underwood wasn't immediately returned to ABC News.
To be fair, Myles admits no one should be sending Underwood nasty messages over this.
"I did feel badly that she's been getting a lot of mean tweets from fans of the movie," he said.
As to whether he'll watch the show tonight, Von Trapp Derbyshire is on the fence. The original idea was to boycott the broadcast, but he said after speaking with his mother, who is trying to be positive about the situation, she might have convinced him to watch.
"We need to be educated," he said. "We can't walk in Friday morning to work or into a conversation without knowing what happened."