Dies Irae (Day of Wrath) is a famous thirteenth century Latin hymn thought to be written by Thomas of Celano. It is a Medieval Latin poem characterized by its accentual stress and its rhymed lines. The meter is trochaic. The poem describes the day of judgment, the last trumpet summoning souls before the throne of God, where the saved will be delivered and the unsaved cast into eternal flames.

Although composers as diverse as Haydn to Liszt to Berlioz used the motto in their works, Sorabji’s use of Dies Irae can probably be linked directly to Charles Valentin Alkan’s use of the same motto in his Symphony for piano solo. As Sorabji’s love for Bach initially manifested itself through Busoni, his nearly twenty year obsession with the plain-chant could have come from the obscure French master whom he thought so highly of. Alkan’s presence in the Opus Archimagicum is felt throughout, not only in the second presto movement with its similarity to the “hands united” movement from Trois Grand Etudes, but in particular the preludio corale movement, which, in addition to featuring the plainchant, possesses a particularly Alkanian sensibility in its use of basso registers for dramatic effect and overall draconic sensibility. It seems that Sorabji may have been additionally attracted to Dies Irae due to its dramatically sinister implications of eternal damnation and its Catholic origin, a religion which was to interest him very much from the standpoint of an almost baroque theatricality.

Sorabji’s first attempt to use the piece in a major work was in his Variazioni e fuga triplice sopra Dies Irae per pianoforte (1923-26), a mammoth series of variations in three parts, the third part a fugue. He seemed dissatisfied with results, although the Seven Deadly Sins section of the second part is quite striking in its programmatic novelty for the time. Sorabji moved on to develop his multi-movement style before adopting the Dies Irae explicitly in the Preludio Corale movement of the Opus Archimagicum. This movement is unique in that the main theme fights for attention with two other similarly developed mottos, the B-A-C-H and G-A-B-E from the dedicatee Bernard Bromage’s name.

At the head of this movement, Sorabji develops the entire plainchant in an extended introduction not unlike the introduction of Liszt’s Ballade no. 2 in B Minor, then departs from this approach by casually developing certain fragments of the chant as it suits him in an almost fantasia-styled manner with ensuing episodes that seem to reject the structural rigidity of a typical theme and variations device. Ultimately, Sorabji creates many layers of richness and unpredictability to the plainchant, sonically maintaining the elegiac tone and aura of mystery that has enshrouded the motto over centuries.

Sorabji returned to using Dies Irae subsequently, but more as a quotation in the work St. Bertrand de Comminges: He was Laughing in the Tower. His final and total mastery of the chant originated in what may be the finest specimen of the theme and variations-genre, the Sequentia Cyclica super “Dies Irae,” in which his use of Dies Irae meets its ultimate summit in a roughly six-hour long set of twenty seven variations, transporting the entire chant through a variety of different musical worlds, permutations, and ersatz developments to a stunning and apocalyptic finale.