There’s nothing like a bit of Mozart to help you unwind… and this was far more than a bit of Mozart.  Part of the CBSO’s “Relax and Revitalise” series, this concert did exactly what it said on the brochure, with Mozart’s skill and varying colours in the hands of the CBSO and its fabulous Chorus making for a thoroughly entertaining evening.

Mozart’s penultimate symphony, Symphony no. 40 in G minor was uncommissioned and, together with nos. 39 and 41, was written in a six week, presumably intensely personal period.  The rare, tragic key adds to the sense of inner emotion and turbulence, with plenty of turmoil, dissonance and disruption injected into the symmetry, poise and structure.

There’s an atmosphere of urgency from the outset, the CBSO adding warmth and vigour to the flowing, swaying rhythms, accented by horns and woodwind.  The deeply affecting slow movement saw Andris Nelsons throttling back so determinedly by leaning against his podium, causing an errant creak or two to find their way into the soundscape.  Legato warmth contrasted with staccato phrases.  A lovely flute solo was followed by layers of strings, woodwind fading into the distance then emphatic strings once more, Nelsons delivering a cheeky little wave to signal a perfectly-placed trill. The orchestra’s commitment to the syncopations of the minuet had visual as well as aural appeal, and that togetherness was carried through into the final movement of tumultuous propulsion.

The first half concluded with a couple of arias for tenor and bass respectively, presumably to add a certain balance to the dominance of the lady soloists after the break. Tenor Ben Johnson gave us Misero! O sogno – Aura che intorno spiri, his sweet intense voice portraying the anguished solitude of a prisoner, the orchestra menacing in the background. One member of the orchestra took centre stage, however, for Per questa bella mano, Mozart’s only solo for double bass.  John Tattersdill partnered the rich vocal bass tones of Vuyani Mlinde in this very unusual love song. It was very accomplished, but I’ll confess it wasn’t my favourite part of the programme as I don’t think it was Mozart’s finest hour.

I always feel it’s a measure of an orchestra’s skill and musicality if at the end of a choral piece I realise I’ve only truly been concentrating on the singers, the instrumentalists having supported in the best possible unobtrusive sense. So it was tonight, with the Chorus as its usual on shining form. It’s just a year until Nelsons’ final concerts with the CBSO before his move to Boston; let’s hope Chorus Director Simon Halsey isn’t planning a departure, as it’s astonishing what he can achieve with a mass of people who are, after all, amateurs.

Like his Requiem (unfinished due to his death), Mozart’s Mass in C minor was also left incomplete (no Agnus Dei, the Credo ending after Et incarnatus est), for less clear reasons. It’s generally understood that the composition was embarked upon as a result of Mozart’s pact with heaven on his marriage to Constanze. One of the soprano solo parts was written to showcase his wife’s considerable technical prowess. Unfinished though it is, the Mass is studded with gems, from operatic skill to Baroque counterpoint and double-dotting grandeur, eight-part chorus and rich orchestration, and tonight it was a real joy to hear.

Orchestra and Chorus seemed as one, as the first female entries emerged almost organically through the introductory music of the Kyrie.  The attack on the Gloria was one of the most explosive and dynamic entries I’ve ever witnessed – simply infectious.  By contrast, we were treated to a stately, heartfelt Qui tollis, displaying extraordinary breath control and outpouring of souls into the word “miserere”; lovely harmonies in the majestic Jesu Christe and such confidence in the Cum Sancto Spiritu fugue that they made it look easy; immaculate diction in the Credo and tingling excitement in the Hosanna section of the Sanctus.

Soprano Malin Christensson, who was a late stand-in, was especially pleasing on the higher, floating passages, and Christine Rice (in Constanze’s prominent role) oozed rich tone, energy and engagement. The quartet of soloists prefaced the double chorus’s final spectacular flourish to this epic masterpiece, which was followed by truly revitalised applause.