Requiem
Mass for the dead.
What it means
The Requiem is the Mass for the dead of the Catholic liturgy and at the same time the designation for its musical setting. The name comes from the opening word of the introit, in which rest is asked for the deceased. Compared with the ordinary Mass, the Gloria and Credo are absent; added are texts of their own, among them the sequence Dies irae, the Offertorium, the Agnus Dei with a changed ending, and further chants such as Lux aeterna and Libera me.
Musical use
The genre reaches from monophonic chant through the polyphony of the Renaissance to large-scale works of the nineteenth and twentieth centuries. Which texts are set is not uniform: some composers omit the Dies irae, others expand it into the most extensive part, yet others assemble their own text compilations and thereby leave the liturgical frame. The character reaches from restrained mourning to a dramatic depiction of judgment. For performers it must therefore first be clarified what layout a particular work has.
Performance practice
Get an overview of the sequence of texts and the characters of the movements, so that the shaping does not become uniform; especially in long works, the alternation is decisive. Plan your strength over the whole duration, especially if extensive choral movements stand at the end. Fix the Latin pronunciation and the syllable distribution in a binding way. Watch for clarity of text in dramatic sections. For liturgical use, the order is to be coordinated with those leading the service; in concert, a brief explanation of the sequence of texts in the programme is worthwhile.
Bear in mind that the choice of texts differs from work to work: some settings omit parts, others add foreign texts and thereby leave the liturgical frame. Check this before planning a programme and explain the layout in the programme booklet. Note that Brahms, for his German Requiem, used Bible texts...
Check whether a setting is usable liturgically before scheduling it into a service.