Astonishingly, it took Handel only twenty-four days to write the orchestral music for the Messiah oratorio—today perhaps the world’s most famous musical composition, one performed thousands of times every year around the world. The magnificent work reaches its climax nearly two hours after it begins with the most famous part of the oratorio, the “Hallelujah Chorus.”

As the trumpets and timpani announce the beginning of the chorus, voices layer on top of each other as the choir sings the words of Revelation 11:15: “And he shall reign for ever and ever.” It is a triumphant declaration of the hope of eternity in…