Take a quick look at the Top 10 songs on iTunes today, and you’ll see all the usual suspects: Robin Thicke, Katy Perry, Lady Gaga, Miley Cyrus, Eminem.

But take a second look, and you may notice a short little lullaby called “Oh Sweet Lorraine” that’s currently the ninth most downloaded song in the country. Where’d it come from?

Well, from an unlikely source: Fred Stobaugh, a 96-year-old Illinois man with no previous musical experience, who lost his wife of 73 years, Lorraine, in April. On a whim, the widower entered a songwriting contest that he saw advertised in a local paper with a love song he’d written for his bride.

Green Shoe Studio, the company running the contest, couldn’t accept his handwritten entry (the competition was digital-only), but they were so touched by his story that they decided to produce his song — and a short documentary about it — anyway. That video, which was posted in July, recently went viral, and the exposure has sent “Oh Sweet Lorraine” soaring up the charts.

“She was just the prettiest girl I ever saw,” Fred says of meeting Lorraine in 1938. “Real timid-like. I just fell in love with her right there.” The couple married in 1940 and had three children and four grandchildren. They would have celebrated their 73rd anniversary in June. “After she passed away, I was just sitting in the front room one evening by myself, and it just came right to me,” he says of his song. “I just kept humming it and singing it. That’s how I came to write it. It just fit her.”