Don't Worry. . . Be Happy.
Source: Song title; found at Journey in Word, ed. Cyndi Craven; an internet collection of quotations
-- Bobby McFerrin, (Mar 11 1950-____), US jazz singer, songwriter, director; He is famous for his unaccompanied jazz styled improvisation; had first #1 acapella pop single: Don't Worry Be Happy, 1989.