Mozart didn’t, of course, write a work called David, König in Jerusalem. He did write Davidde penitente, a short oratorio which draws most of its music from the C minor Mass; it was performed twice, for the Viennese musicians’ charity, in 1785, then probably never heard again in Mozart’s lifetime. He also wrote, rather earlier, some very fine music for a play, Thamos, König in Ägypten. The present work is a compound of these, or music excerpted from them, with five other arias, all translated into German, and interspersed with a spoken text, to tell the scriptural story of David, his heroic deeds and his failings, more comprehensively than Mozart and his librettist managed to do.

I welcome the opportunity, which is rare, to hear music from these rather neglected works: there are fine things in them, especially Thamos, which are scarcely familiar, and the two supplementary arias Mozart wrote for Davidde (to add to the excerpts from the Mass) are rarities, beautifully scored pieces that deserve a hearing. But I have grave doubts about this way of doing it.

Leave aside the lengthy, solemn excerpts of biblical German, uninterestingly presented here (you can easily skip them): the real problem lies in the presentation of Mozart’s music. And this is not sensitively done, to put it mildly. I have no objection to the translation and adaptation needed, or to how it is done. But I do take exception to the dismemberment of Mozart’s music. You cannot tamper with Mozart’s forms and expect them to work.

Several times, a movement is too long for the Procrustean arranger, Richard Bletschacher: so it is cut short. Mozart would not have countenanced (and other listeners, too, will surely find it painful) the ending of a piece part-way through, in the wrong key. Or, more perversely, on one occasion, the inclusion of a modulating coda, preparing (in the Davidde context) for a next item which doesn’t come. Then in one number the secondary material is cut in the exposition section but retained in the ‘recapitulation’. Perhaps the most absurd antic comes near the end, where three soloists are given a florid little piece which on its own makes no sort of musical sense: this piece was composed by Mozart, for Davidde, as a sort of cadenza within a chorus (originally part of the Mass) – and the chorus is then performed without it. Excerpts snatched from the Flute and Harp Concerto stand for David’s harping.

Some of the concert arias fit acceptably into their new contexts, notably ‘Io ti lascio’, assigned to Uriah as his farewell to Bathsheba. But some are formally violated (of the lovely ‘Se al labbro’ – noted incorrectly in the booklet, by the way, as from Davidde – only part of the first section of a three-section aria is given); and I cannot think what possessed Bletschacher to include ‘Va, dal furor portata’, written in London when Mozart was a boy of nine and stylistically worlds apart from the rest of the music.

All this, of course, begs another question: whether music conceived in one dramatic sense can effectively be transposed to serve another, as is asked of some of it – too big an issue to deal with here, and all I shall say is that sometimes it works pretty well. That said, the performances are of a high standard, conducted by an assured Mozartian with a good feeling for tempo and texture and a fine command of the big choruses. The solo singing is by and large excellent. Alison Browner contributes shapely singing in Jonathan’s aria, Sibylla Rubens brings some drama if slightly shallow tone to the young David and later to Bathsheba. Of the two tenors, Johannes Chum gives a clean, direct account of ‘Va, dal furor’ and Christian Elsner, weightier in tone and expression, sings his two arias (one is ‘Se al labbro’) with much style and grace, in the best tradition of lyrical German tenors. The two basses also impress, Franz-Josef Selig for his warm singing of Saul’s aria, Oliver Widmer for his nicely shaded performance of Uriah’s.

In all, then, this set, this work, seems to be misconceived, but none the less there is a lot of music and a lot of music-making here to enjoy. The booklet, by the way, provides a full text in German, but only a brief outline in English and French, which means that non-readers of German won’t know what some of the arias are about.