The quirky children’s program “The Banana Splits Adventure Hour” launched in 1968, 16 years before Patrick Stumph, lead singer and guitarist for Fall Out Boy, was born. That wasn’t a problem when he was hired to write the score for “The Banana Splits Movie,” a new horror film featuring Fleegle, Bingo, Drooper and Snorky that was released on DVD and Blu-ray last month.

“I come from a giant Catholic family so I have plenty of aunts and uncles who are the right age to have grown up with the show,” Stumph says. “I was this weird little island of a mid-’80s, ’90s kid and so I inherited a lot of ’70s culture.

“I experienced a lot of the ’70s, but second hand.”

What was passed down to Stumph was “The Banana Splits Adventure Hour,” an hour-long, variety-style children’s show that followed the antics of a fictional rock band composed of four animal characters. There were 31 episodes produced by Hanna-Barbera (a company better known for their animated work) that originally ran from 1968-1970 and then in syndication from 1971-1983.

“The Banana Splits Movie” takes a very different approach with the characters. Harley (Finlay Wojtak-Hissong), a superfan of the Banana Splits, gets tickets for he and his family to attend a taping of the group’s TV show. Cancelation of the program sparks a night of terror for the audience members.

The one thing that was already engrained in Stumph’s mind before he started working on the project was the show’s theme, “The Tra La La Song,” written by Mark Barkan, who also wrote for The Monkees, Archies and Manfred Mann. It was such a familiar tune to Stumph that he assumed it had always been around, much like “Jingle Bells.”

“I didn’t realize it was a part of the show until I worked at a huge record store when I was in high school,” Stumph says. “Then I got acquainted with the Banana Splits and I just thought it was nuts.

“It’s a great song and the show is great, but really weird. People know the song without knowing where it came from.”

The theme song has become so iconic that it was the one part of Stumph working on the score where he was given limitations. Director Danishka Esterhazy asked him not to change the song as the upbeat nature would be a nice counterpoint to the darkness of the film. Stumph was on board with that idea because he was certain the project called for a straightforward approach to the tune. He did get to indulge his creative side reprising the song in some very different ways throughout the movie.

Stumph is best known for his work onstage, but the Grammy-nominated Chicago native has been behind the melodies to the band’s hit songs. He loves performing, but one of the things Stumph loves to do when he gets in a recording studio is to throw a variety of musical ideas at the wall and see what turns into the right sound.

“A score likes this needs you to take that approach. By nature, you can’t keep doing the same thing for two hours because it is going to wear on people,” Stumph said. “So you have to keep coming up with weird stuff.

“It was really exciting for me because I tend to play around with a lot of instruments myself. In this score, I play everything. I’m not a virtuoso horn player, but as I am figuring out the score, I will realize I have come up with something and will go record that. I’m always discovering stuff when I am doing something like this.”

A bonus for Stumph with “The Banana Splits Movie” was that the entire movie was completed before he started working on the music. There have been other jobs where he was only able to see part of the film and read the script when the scoring process started. He had only a couple of weeks to produce the music for “The Banana Splits Movie,” but while Stumph finds that time limitation draining, it’s also a fun process for him.

Stumph is building up a solid resume of scores and tunes that he has created for TV shows and films such as “Gnome Alone,” “I Love You, Beth Cooper,” “One Tree Hill,” “Spell,” “Everybody’s Everything” and “Changeland.” All of the scoring work started with the Incredible Hulk. Stumph’s first foray into scoring was for the on-ride audio system for the Incredible Hulk Coaster at Universal’s Islands of Adventure theme park in Orlando, Fla.

“I kind of bluffed my way into it,” Stumph says. “They were kind of looking for a pop song and I asked them if I could use an orchestra. They said it was OK if I wanted to do that. Because the ride is only two minutes, I asked if I could write music for when people are just standing around. They were like ‘sure.’

“I got to record with a symphony orchestra. It’s one thing to say I want to score and be a composer but I didn’t have anything yet. It’s another thing to be able to say this is what I have done for Universal Orlando. That’s a big part of how I end up here.”

“The Banana Splits Movie” also stars Dani Kind, Romeo Carere, Steve Lund and Sara Canning. Fleegle, Snorky and Drooper are voiced by Eric Bauza.