When Green Shoe Studio advertised in Illinois for a singer-songwriter competition, it received an unexpected entry.

It was from a 96-year-old Peoria resident named Fred Stobaugh. His wife of nearly 73 years had recently died, and he saw the ad for the contest in the newspaper.

"After she passed away, I was just sitting in the front room one evening by myself, and it just came right to me," Stobaugh said in a Green Shoe Studio video, which has been viewed more than half a million times.

The contest asked for people to submit YouTube videos of them performing their entries.

"Instead of a video, we received a very large manila envelop with the letter he [Stobaugh] sent us," Green Shoe Studio producer Jacob Colgan said in the video. "It was just so heartwarming, and we said, 'Fred, we're going to record your song."

Fred Stobaugh, 96, of Peoria, Ill., whose wife of nearly 73 years died in 2013, wrote a song about her that has gone viral. Green Shoe Studio/ABC News

Stobaugh had written on the envelope, "P.S. I don't sing. I would scare people. Ha-ha."

"It was just so cute how he wrote it," Colgan told ABC News. "He wanted her to know that he loved her still."

The song is called "Sweet Lorraine" and included the lines, "Oh, sweet Lorraine, I wish we could do all the good times all over again."

"We met up with him a couple times and just kind of played some songs back and forth," Colgan said of the process of turning Stobaugh's lyrics into a professionally produced song.

"He decided to put it to a guitar so I brought my guitar and just messed with it for a week or so," Colgan said. "He really wanted to do a good job and stay true to his original lyrics."

Stobaugh met his wife, Lorraine, in 1938 when she was a car hop at the A&W root beer stand.

"She was just the prettiest girl I ever saw," Stobaugh said. "I just fell in love with her right there."

The couple dated for two years and then got married.

The music studio set Stobaugh's lyrics to music and recorded the song with professional musicians and a professional singer. When Stobaugh heard the song for the first time, he cried.

"It was a wonderful 75 years," he said. "I really, really miss her."

The song "Oh Sweet Lorraine" is available for purchase on iTunes.