Tom Whitlock, an Oscar-winning songwriter who helped “Top Gun” and its soundtrack soar to the heights of 1980s culture, writing the lyrics for the chart-topping love theme “Take My Breath Away” as well as the hard-rock anthem “Danger Zone” — a song that conjured up images of motorcycles, fighter jets and speed-demon pilots for a generation of moviegoers — died Feb. 18 at a memory care center in Nashville. He was 68.

His death was confirmed by Gorman-Scharpf Funeral Home in his hometown of Springfield, Mo. A longtime friend, Larry Lipscomb, said Mr. Whitlock had Alzheimer’s disease.

Together with his musical wingman, Italian composer Giorgio Moroder, Mr. Whitlock co-wrote songs that helped turn “Top Gun” (1986) into a pop culture phenomenon. Directed by Tony Scott and produced by Don Simpson and Jerry Bruckheimer, the film was a flashy, crowd-pleasing celebration of naval aviators, male friendship, beach volleyball and aviator sunglasses, starring Tom Cruise in the role that made him one of Hollywood’s biggest stars, as hotshot pilot Pete “Maverick” Mitchell.

While it opened to mixed reviews, the film grossed more than $350 million worldwide, more than any other movie that year. It leaned heavily on its soundtrack: The opening sequence started with a synthesizer theme from German composer Harold Faltermeyer, as fighter jets moved into position on the deck of an aircraft carrier, and then launched into “Danger Zone,” performed by singer and guitarist Kenny Loggins. “Revvin’ up your engine, listen to her howlin’ roar,” he sang, before inviting audiences to take a “highway to the danger zone.”

“This movie seems determined to break the sound barrier,” wrote New York Times reviewer Walter Goodman. “If it isn’t the roar of the jets, it’s the roar of Maverick’s motorcycle, and when that subsides, there’s always the clamor of the music,” which one critic described as “martial hard pop.”

Audiences couldn’t get enough of it. The soundtrack sold more than 9 million copies and topped the pop chart for five weeks, propelled by singles including “Danger Zone,” which reached No. 2 on the Billboard Hot 100, and the dreamy ballad “Take My Breath Away,” sung by Terri Nunn of the new wave band Berlin. The track won an Academy Award for best original song, although Mr. Whitlock said he had trouble holding on to the Oscar statuette.

“Every time I got up from the table” during the after-party, he recalled, actor Dennis “Hopper would hide my Oscar someplace.”

Mr. Whitlock, an unassuming Missouri native, was somewhat unusual in a show-business world known more for big egos and brash personalities. “He came across like a real nuts-and-bolts, on-the-level guy. I loved that,” Nunn said in a phone interview. “There just aren’t a lot of those guys in music. We’re generally weird people — he was not. He was just really a nice guy.”

He was also a versatile musician, learning the drums at age 11 before writing songs on the piano. He moved to Los Angeles in 1983, hoping to make it in a rock band, and later recalled arriving in town “with four hundred bucks in my pocket and a 1970 Volvo without a front seat, so I could fit my drums in there.”

But he found that it was too expensive to book rehearsal spaces for his band and began working odd jobs at recording studios, including the former Davlen Sound Studios in North Hollywood, where he said he came in one day to help a friend remove speakers from the control room. “While we’re there up on ladders the back door slams, and this guy comes down the hall with this amazing Italian accent, dropping every curse word ever invented in multiple languages,” he said in 2013, looking back on his career as part of a local music series in Springfield.

It was Moroder, who had recently bought the studio and, according to Mr. Whitlock, was complaining about the brakes on his Ferrari. Mr. Whitlock offered to take a look and ended up replacing the brake fluid. He was soon hired as an assistant at the studio, where he cleaned the floors, picked up bagels, ordered groceries for the composer’s mother and, in his spare time, learned the ins and outs of the recording business, cutting demos of his own songs on the side until Moroder discovered that he wrote lyrics, too.

When the composer’s usual songwriter partners were busy on other projects, Moroder asked Mr. Whitlock to fill in. “Giorgio needed a lyricist and there I was — minimal talent but maximal proximity,” he said in a 2014 interview for Kickin’ It Old School, a culture blog.

Mr. Whitlock was underselling his talent. “I always let him do whatever he wanted,” said Moroder, a three-time Oscar winner, in a phone interview. “I’m not good at lyrics, and I trusted him.”

The duo went on to co-write the theme song for the 1988 Summer Olympics in Seoul, “Hand in Hand,” as well as the theme for the 1990 World Cup in Italy, “To Be Number One.” They also worked on movies including “Beverly Hills Cop II” (1987) and the Sylvester Stallone films “Rambo III” (1988) and “Over the Top” (1987), which featured Loggins performing their Top 40 single “Meet Me Half Way.”

But they remained best known as a duo for their work in “Top Gun.”

Their song “Take My Breath Away” impressed the filmmakers so much, according to Mr. Whitlock, that they decided to film a love scene around the track, shooting new footage between Cruise and co-star Kelly McGillis after the production had wrapped.

“Danger Zone” took a little more time to come together. The song was reportedly offered to Rod Stewart, Toto, Kevin Cronin of REO Speedwagon and Mickey Thomas of Jefferson Starship, and was tweaked by Loggins after he agreed to record the track. The singer made a few changes to the chords and lyrics, much to the annoyance of Mr. Whitlock, who praised Loggins’s “masterful vocals” but criticized his work as a lyricist. “Anything that makes you cringe is Kenny’s fault — like, ‘You’ll never say hello to you / Until you get it on the red line overload.’ Give me a break,” he said. “But he’s Kenny Loggins, and I’m not.”

The changes stuck, and the song endured, kicking off the sequel “Top Gun: Maverick” (2022) in a nearly shot-for-shot remake of the original film’s opening.

The younger of two children, Thomas Ross Whitlock was born in Springfield on Feb. 20, 1954. His father, a lawyer, died when Mr. Whitlock was 5. His mother went on to raise him as a single parent, supporting his musical ambitions by allowing him to practice with his friends in the garage even as some neighbors were less tolerant of the noise.

“Well, you know how young boys like to start little bands,” she told the Springfield News-Leader in 1987. “The police came by a couple of times,” she added, but “Tom was usually pretty considerate when he played his drums.”

Mr. Whitlock performed as a fill-in drummer for the Ozark Mountain Daredevils, a local band that released a pair of Top 40 hits, and studied music theory and composition at Drury College in Springfield. Eager to launch his career, he left the school — now a university — before completing a set of piano proficiency exams.

The school awarded him a bachelor’s degree in 2012, according to the News-Leader, shortly after Mr. Whitlock was honored by the American Society of Composers, Authors and Publishers at a Library of Congress event in Washington.

His marriage to Hollie Sherman ended in divorce, but the couple remained close, with Mr. Whitlock’s ex-wife caring for him after his Alzheimer’s diagnosis, friends said. Survivors include his sister.

After finding success in Hollywood in the 1980s, Mr. Whitlock built log cabins and recording studios, including in Bellingham, Wash. He also drummed, cut records and wrote songs — “all the usual stuff that an aspiring songwriter does,” as he put it in the 2014 blog interview.

“Ambitions? I’d like to meet somebody who’d give me some more amazing melodies,” he added, “and I’d like to meet a singer that can rip your heart out. Regrets? None.”