As a scholar once quipped in relation to Mozart’s final work: ‘Requiem, but no Piece’. Mozart’s Requiem has been a site for controversy since almost the time of the composer’s untimely death, and it is clear that it is never going to be complete, at least as a piece by Mozart. On the other hand, it is perhaps testimony to the quality of what does survive that musicians and scholars have given it such persistent attention. While some of its popularity can be attributed to romantic notions of the dying genius doing his utmost to crown his life’s work in the most sublime fashion, there is no doubt that the vast proportion of the surviving material is remarkable in its musical cohesion and emotional power.

In the early nineteenth century, the controversy was over how much of the Requiem was really the work of Mozart and how much of it was completed by Franz Xaver Süssmayr. By the turn of our current century, the extent of Süssmayr’s involvement had been clearly established – so far as is likely to be possible – and the discussion moved towards the question of whether modern scholars could provide a completion superior to Süssmayr’s. Now that there are a number of ‘new’ versions of the Requiem, perhaps performing the ‘original’ completion is almost as controversial as performing a modern version

If Süssmayr’s completion does contain obvious weaknesses in terms of certain movements (most obviously the ‘Sanctus’ and ‘Osanna’), and of various details of part-writing and orchestration, Süssmayr remains the only figure in this who actually knew Mozart and shared essential elements of his musical culture. Moreover, it was Süssmayr’s version that was known as ‘the’ Mozart Requiem for countless musicians and listeners until the last decades of the twentieth century. It provided material that finds echoes in several major composers (Verdi, Bruckner and Fauré immediately come to mind), so it would surely be wrong to discount a large period of productive reception on the pretext that inspired listeners were hearing partly in error.

The recent publication of David Black’s new edition of Süssmayr’s version provides an excellent opportunity to record the original completion yet again. Not only does the new edition show very clearly the areas completed by Mozart and the precise extent of Süssmayr’s additions, it also presents several details that have been obscured by later ‘improvements’, particularly those added in the first published edition (which does not mention Süssmayr), by Breitkopf & Härtel in 1800. Black’s new edition therefore returns the work to the state it was in during the first, crucial years of its exposure to the public, and this in turn provides an ideal opportunity to consider how the work may actually have sounded at its very first performance.