In 2010, the Colombian army produced a song called ‘Better Days’ with Morse code embedded in the chorus and aired it in rebel-controlled territory to lift the morale of hostages. The message said “19 people rescued. You are next. Don’t lose hope.” – WTF Fun Facts
Source: https://www.theverge.com/2015/1/7/7483235/the-code-colombian-army-morsecode-hostages
