“Don’t Worry, Be Happy” is a song by American musician Bobby McFerrin released in September 1988. It was the first a cappella song to reach number-one on the Billboard Hot 100 chart, which was a position it held for two weeks.
Originally released in conjunction with the film Cocktail in 1988, the song originally peaked at No. 88 on the Billboard Hot 100. The song was re-released the same year and peaked at No. 1 on September 24, 1988, displacing “Sweet Child o’ Mine” by Guns N’ Roses. Wiki