Mozart’s Requiem, his last and unfinished composition, is one of the most famous choral works in the classical repertoire, a masterpiece whose genesis in several respects is shrouded in mystery. This of course adds to the fascination of a work in which Mozart, raised a Catholic and a devout member of the church throughout his life, reveals his deep respect towards death with vivid musical imagination – his ‘true, best friend’, as he writes in a letter to his father.

The music is sometimes comforting, sometimes harsh and emotionally stirring, as one hears in the ‘purgatory fire’ of the Dies irae. Mozart only fully completed the first two movements (Requiem and Kyrie); for another seven movements and the first eight bars of Lacrimosa we have the vocal parts and the figured bass. The remaining parts including the instrumentation were completed by his student Franz Xaver Süßmayr, who had discussed the Requiem with Mozart himself and worked partly on the basis of his sketches. The Sanctus, Benedictus and Agnus Dei are compositions entirely by Süßmayr.

A number of interesting alternative attempts to complete the Requiem have been made during the last century, but the importance of Süßmayr’s contribution to the work’s fame and a proof of its authenticity of style might be deducted from (the keen Mozart expert) Beethoven’s famous purported statement: ‘If Mozart did not write the music, then the man who wrote it was a Mozart.

By its nature, this SAM-Klang edition occasionally challenges the performers with a somewhat higher level of activity than in the original SATB version, and in some places a slight redistribution of entries in the polyphonic sections has been made. Despite this, the original orchestral accompaniment can be used together with this version without restraint, and the work can also be performed with piano accompaniment. Some pieces in this volume feature brackets that comprise ‘ternary cells’ – cells of three beats – of differing lengths. Before the mid 17th century in the stile antico, it was common for each vocal line to have an independent stress pattern: a sequence of binary or ternary accentuations guided by the declamation of the text in order to give life to each voice. Despite the non-legato of the individual single layer – created by elements including the musical articulation, the (hairpin) phrasing of the ternary cells and a natural text declamation – the constant displacement of stresses between the voices provides an overall feeling of flow right through to the next cadence, at which point the ‘cells’ come together. Certain characteristics of this style, such as hemiolas and cadential conventions, survived in the following centuries and can be found in the music of Haydn, Mozart, Schubert and Brahms, and even later composers with an affinity for vocal polyphony.