Requiem: Dies Irae

The thunder of the chorus erupting on the word "Dies irae" — Day of Wrath — is one of the great shock openings in Western choral music. Mozart's Requiem, left incomplete at his death in 1791 and completed by Franz Süssmayr, opens this movement with a full choral attack of terrifying density, the text describing the apocalyptic final judgment in terms that leave no room for comfort or negotiation. The orchestration amplifies the dread: timpani, brass, and strings driving forward in a relentless dotted rhythm that suggests an entire civilization marching to its reckoning. The soprano and bass voices alternate in rapid declamation, the choir responding in dense homophony — everyone singing the same rhythm simultaneously, which creates a mass-unanimity effect unlike the dialogic texture of the preceding Introit. The movement is short, barely over a minute, functioning as a structural jolt before the longer movements that follow. Mozart's sketches for this section were extensive enough that Süssmayr's completion reflects the composer's intentions closely. It remains the defining musical statement on eschatological terror in the classical repertoire — a piece that sounds genuinely afraid.