't Is OK was the Dutch entry in the Eurovision Song Contest 1978 in Paris performed by the trio Harmony. The song is an up-tempo number about the power of a happy song itself. The band explains that all one needs to brighten one's day is to sing a song "happy and in harmony". The song was performed eleventh on the night, following Belgium and preceding Turkey. At the close of voting, it finished in 13th place with 37 points.