Many people find comfort in music. They find encouragement in the lyrics, or they allow the upbeat tempo of the music to lift their spirits. In one case, there was a message of hope that went beyond the words and melody. It was a secret message intended to boost the morale of a few select recipients.

The Revolutionary Armed Forces of Colombia (FARC) was a group of communist guerilla insurgents operating in rural Colombia. FARC’s tactics included mass kidnappings, abducting thousands of people over a fifty-year period. Some of the captives were held for over ten years as FARC used them to try to get ransom or political demands.

Sixteen members of the Colombian military were being held captive in 2010. Finding the location of the captives was only part of the solution. FARC’s practices frequently involved the immediate execution of any hostage when a rescue was attempted. If the hostages were going to survive a rescue attempt, they would somehow have to get advance word so they could be on the alert and ready to fight back or run into the jungle. The danger, of course, in trying to send a message was that the FARC captors would intercept it, thus defeating the purpose of sending the message in the first place.

Former hostages noted that captors frequently permitted the hostages to listen to the radio. Col. Jose Espejo, leader of the rescue operation, looked for a way to send a message through the radio that would be unlikely to be detected by the guerillas.

Espejo worked with a team of musicians and audio engineers to develop “Better Days” by Natalia Gutierrez Y Angelo. The song, on its face, appeared to be just one more example of the popular music on the top charts. Worked within the song’s melody was a message in Morse Code, timed to the song’s rhythm. Soldiers, trained in Morse Code, were more likely to detect the message than the untrained FARC captors.

“Better Days” went out through rural Colombia, thanks to the government-owned radio stations throughout the country. An estimated 3 million people heard the song. Among them were the hostages and even the FARC captors, who apparently enjoyed the song and sang along with it. The captors were oblivious to the hidden message: “19 people rescued. You are next. Don’t lose hope.”

The operation was a success. The hostages were rescued, and the song remains a popular reminder that the title, “Better Days,” was a promise fulfilled.

Listen to a clip of the song with the hidden message highlighted here:

Read about the escape maps hidden in playing cards that helped WWII POWs.

Read more fun facts about music.