An a cappella song from 1988 by American jazz artist Bobby McFerrin, used in many movies (like Wall-e, Casper, Flushed Away, for example) and with many curious details. Often said it is by Bob Marley, but the Jamaican passed away in 1981, eight years before this song was written. But yes, it is a reggae tune.
There are at least a couple of interesting covers, one in Greek language by Katsimihas Brothers, and another in Montenegrin by Rambo Amadeus, this one with the opposite title meaning.
Here's for Radio
Bermuda the original 1988 Bobby McFerrin Don't Worry Be Happy with a Wall-e wallpaper.
