The basic Requiem text is more or less agreed, although its use in music has fluctuated somewhat according to the direction of the church and the conscience of the composer. Composers divide up the Requiem mass differently. Sometimes modern texts supplement or replace all or part of the traditional text; a trend started by two of the all-time greats, Johannes Brahms (Ein Deutsches Requiem) and Robert Schumann (Requiem fuer Mignon, oddly, a requiem in honor of the death of a fictional character). Whatever the final text, the composer of a Requiem is expected to base their work on a musical exegesis of the spiritual themes of the original, and to integrate the ancient musical themes which are closely associated with them. These necessary similarities and the extraordinarily high quality of composition make Requiem masses an excellent point of comparison between composers, especially with regard to comparable segments of text.
The Dies Irae is one of the most enduring movements of Requiem masses. It's often included even where other texts have also interceded. This is presumably because the Dies Irae is FREAKING AWESOME. (If you disagree on this point, either 1. you've never heard it; or 2. we probably can't be friends.) It's essentially a condensed book of Revelations, focusing on the final Judgment. Musically, it is closely associated with a 13th century Gregorian plainchant hymn. Later composers, particularly after Mozart, have cranked up the terror on "day of wrath," hitting the opening of the movement with everything they've got. Following the opening tumult, the composer backs off into a more contemplative mood to consider the implications of Judgment. Resurgent fear often intervenes, either in the course of the initial Dies Irae, or in a subsequent Libera Me movement.
Because of its ancient pedigree and ability to be easily recognized, the Dies Irae theme has been borrowed in other contexts by a number of composers to evoke the fear of death and judgment, and the broader theme of death in general. As a musical tool of communication, there is probably no easier way to place these themes in the mind of the listener. When you hear the Dies Irae, shit gets real. In just two bars, the listener is reminded of the coming Judgment. This is sometimes controversial when the Dies Irae is placed in irreverent contexts, as we shall see.
Below I've embedded some notable implementations of the Dies Irae. If you know of others in popular culture, please post them to the comments.
Composer unkown, Dies Irae, plainchant hymn, 13th Century
Wolfgang Mozart, Dies Irae, from Requiem, 1791.
Giuseppe Verdi, Dies Irae, from Messa da Requiem, 1874.
Benjamin Britten, Dies Irae, from War Requiem, 1962
Some other top-notch examples of a classical Dies Irae are found in Dvorak's and Bruckner's Requiems.
Hector Berlioz, Symphony Fantastique, Movement V: Songe d'une nuit de sabbat (1830).
Honorable Mentions:
- Berlioz (Dies Irae, Grande Messe des Morts)
- Dvorak
- Bruckner
- Penderecki
- Liszt ("Tottentanz")
- Rachmaninoff (Variations on a Theme by Paganini, variation X)
>Rice & Webber (Requiem for Evita, from the musical Evita)
>Larson (La Vie Boheme, from the musical Rent)