Colombia's life-saving pop song

It is 2010 and Colombian Colonel Jose Espejo has a problem. Not only is the Farc increasing its kidnapping activity, targeting police and military hostages, but many of the soldiers already in captivity - some kept in barbed-wire cages and held isolation in for over a decade - are losing hope of ever being rescued. Colonel Espejo knew that in order for future missions to succeed, he’d need to warn the captives that help was coming so they could be ready to make a break for it when the army arrived. But how do you get a message across to military hostages without tipping off their captors and placing them in even greater danger? The unexpected solution - hide the message in a pop song with an interlude in morse code that the military hostages could decipher.