This was the second vocal concert of late (the last being Ariodante with Joyce DiDinato) to feature an exemplary female soloist caged inside an otherwise nondescript performance. Jérémie Rohrer tried in vain to force energy out of French chamber choir Les Elements and period ensemble Le Cercle de l’Harmonie. Ultimately though, despite moments of sudden verve from conductor and ensembles, the night belonged to soprano Sally Matthews. Her stunning Et incarnatus est solo in the Credo of the ‘Great’ Mass in C Minor gave us a welcome beacon of virtuosity in an uneven, foggy, night of Mozart. This inspired a momentary revival within the orchestra, who started the subsequent Sanctus with new-found élan - only to fail to sustain it.

Indeed, this was the pattern of the entire performance. The 1782-3 Mass in C Minor in the second half succeeded the beautiful Vesperae solennes de confessore (written in 1780 and often referred to simply as The Vespers) in the first. In performance tonight it was often frustrating, the particularly Austrian personality of lithe, festive brass and moments of strength in the string section failing to keep the momentum of the six movements going. When Bass Nachuel Di Pierro and Tenor Rainer Trost joined Matthews and Mezzo Ann Hallenberg for fleeting but complex vocal quartet moments, the male soloists sung with underwhelming nonchalance. Heads mostly buried in their scores, they were instantly forgettable. However, the Laudate Dominum in this piece, which must rank as one of the most beautiful slices of Mozart’s writing for Soprano voice, shone through in all its beauty, even if Matthews sweet, ripe-toned voice sounded overly operatic against the rawness of Le Cercle de l’Harmonie's timbre. This was also the poorest movement in terms of tempo realisation; the orchestra dragged terribly until gearing up their pace, eventually subsiding into brooding mystery towards the end, as if under Matthews’ spell. Fortunately, the Magnificat brought the first half to a more confident conclusion, the choir displaying their fine blend and attention to detail with their articulation under Rohrer’s authoritative baton.

Luckily, the Mass in C Minor restored the balance in favour of moments of quality after the earlier blandness. What an interesting work the ‘Great’ Mass is, displaying remarkably un-Mozartian hints at Baroque polyphony and scintillating coloratura solos, as well as homophonic chord sequences for the choir, the likes of which we are more accustomed to hearing from Bach. Written after the composer’s brush with music of his preceding musical eras, it remained unfinished at his death and completely lacks an Agnus Dei amongst other missing components of a potentially gargantuan work. The genius of Mozart is perhaps evident in the fact that what he did write remains outstanding in its own right. There are momentary echos of several other of his works (sometimes even Handellian vocal solo writing) in this piece and frequent opportunities for a chorus to indulge in richly textured sequences such as that which opens the Credo. Here and in the opening Kyrie, Les Elements were impressive, injecting bite in their sound. But their energy was patchy, meaning the concert was oddly disorientating. Sometimes we were entertained with brilliance – Hallenburg, for example, distracted us from an eye-catching, voluminous dress and her mannered singing style with a mellifluous and technically accomplished Laudate Dominum (co-incidental considering Matthews’ success in the movement of the same name in the Vespers). It is a shame the brilliance of these two soloists was spoilt by too-slow pacing. To end on a positive note however, showcasing Mozart’s diversity and agility as a composer, with two such different works written just three years apart, was perhaps the most enjoyable achievement of this performance.