Every Good Boy Deserves Favour is a stage play by Tom Stoppard with music by André Previn. It was first performed in 1977. The play criticizes the Soviet practice of treating political dissidence as a form of mental illness. Its title derives from the popular mnemonic used by music students to remember the notes on the lines of the treble clef. The filming was undertaken at a live performance at Wembley Conference Centre in April 1978, conducted by Previn.