Miserere begins on the stark note of human existence. A lone voice begins to sing. In regular, alternating, long and short syllables, the voice intones the opening verses of Psalm 51, the fourth psalm of repentance (“Have mercy upon me, O God, according to Thy lovingkindness … ”). To give weight to what is said, a pause follows each word, appropriate to the sound and sense of the utterance. lnto this reverent stillness, the clarinet gently intrudes with tones from the same chord. The clarinet can accommodate itself to spanning large intervals, thus enabling it to sustain a two-beat against the three-beat rhythm of the singing voice. Each of its arpeggios is followed by a pause before the voice takes up the next word, making sophisticated use of the Hocket technique employed by medieval masters to separate the instrumental from the vocal lines. Later, the warm, deep tones of the bass clarinet begin to provide the first connecting links of sound. lndeed, what is happening here, using the simplest means and a minimum of musical elaboration, is no less than an ushering in of sound anticipating the final drama. That drama comes at the end of the world when the divine, assuming the musical form of the requiem's Dies Irae, breaks in upon the penitential world of man. Between the fourth and fifth verses of the psalm an implacable drum-roll heralds the coming of the Day of Wrath and its rain of fire. The world of man is represented by singers holding the liber scriptus (the Book of Life), who, totally dependent on God's grace, fall silent after a mighty crescendo, and remain so during the first seven stanzas of the Dies lrae interpolation.
Divine wrath bursts in upon the world with great power; the members of a heavenly choir (consisting of angels, the twenty-four elders of the Apocalypse, and the four Evangelists' symbolic animals accompanied by King David) take turns singing the prophetic text of Thomas de Celano (died 1255) without pause and seemingly senza fine. How else could the day of Judgement be represented in the music of man except suddenly and unexpectedly, rendering all conventional methods of creating musical climax powerless?
ln his Dies lrae interpolation Pärt does not employ the well-known Gregorian melody. lnstead, he adopts a strict three-part mensuration canon in which the voices of chorus and instruments descend, step by step, from a great height on the notes of a pure A-minor scale, a procedure which is repeated at every verse and stanza. A trombone proclaims the end of the world, its powerful notes resounding to the awesome event, while the sound of the trumpet leaps up from the molten core to shoot and dart above the fiery chaos.
Although the music has great power here, it does not overwhelm the listener. ln the silence which follows immediately, as well as in succeeding silences into which the composer and his music retreat, one can reflect upon what is heard, albeit as something past and at a distance. ln addition, the silences can serve to assist the afflicted ear by supplying temporary respite (as when, in speaking of the holocaust, there is mention of total sacrifice). Apart from this, it is probably true that anyone listening to Pärt's music emphatically needs the pauses. As the poet of the “Middle Ages” (that is to say, the period which precedes the third millennium), Pärt's pauses are in fact on the one hand, codes which denote human deficiency and on the other, indicators of the beginnings of a completely different kind of music.
Following the silence coloured by the sound of the bell and after the seven stanzas of the Dies lrae, a new beginning unfolds. As at the opening of the work, it is once more a single unaccompanied voice that constructs the world of Miserere. The former tonic now becomes a leading tone, and the first melismata appear. The music rises from the depths to higher spheres, slowly developing from a paralyzing despondency through the finer nuances of dance and then to fullness, depth, and surprising dramatic power.
The additional eighth stanza, Rex tremendae, succeeds in gathering up the enormous tensions inherent in the Miserere. During this segment, the five vocal soloists haltingly repeat some of the syllables from the text sung by the choir, so that, after the descent expressed in thefirst seven stanzas of the Dies lrae interpolation, the listener is finally transported upwards.