A song written and performed by Canadian soldiers at a Japanese prison camp in 1943 gave hope not just for the prisoners of war, but for people back home who didn't know if they were alive.

I'll Never Say Goodbye Again was written by Elmer McKnight, who, along with his brothers Gerald and Melville, served in the Winnipeg Grenadiers during the Second World War.

The Grenadiers and the Royal Rifles of Canada were part of C Force, the Canadian military contingent that fought in the Battle of Hong Kong.

By the time Hong Kong was surrendered to Japan in December 1941, 290 Canadian soldiers were killed and many others were sent to prison camps in Hong Kong, mainland China and Japan.

In the camps, prisoners were forced to work as slaves while being beaten, malnourished and mistreated.

As musicians before the war, the McKnight brothers were allowed to bring their clarinet, saxophone and trumpet into their prison camp. They started a band to help boost morale among fellow PoWs.

"They had been in the Salvation Army brass band before the war," recalled George Peterson, who served in C Force and was at the same PoW camp as the McKnights.

"I guess that's why they joined the Winnipeg Grenadiers, because we had a brass band at that time also."

'Extraordinary' radio transmission

Very little information came out of the Japanese PoW camps. But in 1943, a Japanese propaganda transmission from Tokyo was picked up on shortwave by Canadian and American listening posts.

That transmission featured the Canadian prisoners singing I'll Never Say Goodbye Again, an original song written by Elmer McKnight.

"It's really extraordinary coming from a Japanese prison of war camp," said David Bercuson, the director of the Centre for Military and Strategic Studies at the University of Calgary.

"Of course, what they were trying to do at the time was to claim to the rest of us that their prisoners, in fact, were well-treated."

Bercuson said the transmission also allowed the Canadian prisoners to let people at home know they were still alive.

"In many cases, they weren't even getting mail delivered to them," he explained.

"At least this was an opportunity for them to say, 'Hey, we're here, we did survive that battle, and hopefully we'll be home when the war is over.'"

Became a hit song

I'll Never Say Goodbye Again was played across Canada on CBC Radio as part of a wartime music program in 1944, and the song became a hit.

Canadian government officials made sure the song was published in McKnight's name and recorded for release.

After returning home from the war, Elmer McKnight said the song was inspired by his fiancée, who was waiting for him.

Also waiting for McKnight was a royalty cheque, which helped him and his family start a postwar life.

All three McKnight brothers have since passed away, but I'll Never Say Goodbye Again is still performed today at gatherings of Hong Kong war veterans.

"That's something that I think about every day — not the song, but the life we had as a PoW," Peterson said.