The Baden-Baden Festspielhaus’s concert cycle of Mozart’s mature operas, sponsored by Rolex, always starring Rolando Villazón and conducted sagaciously by Yannick Nézet-Séguin, reaches La clemenza di Tito. As before in this series, the luxury all-star casting is predominantly but not entirely spot-on. Any Mozartian with a pulse ought to be moved by Joyce DiDonato’s passionate Sesto (‘Parto, ma tu, ben mio’, featuring Romain Guyot’s lovely clarinet obbligato, is profoundly touching), Marina Rebeka’s fickle yet eventually heroic Vitellia (the lowest phrases during ‘Non più di fiori’ are uncomfortable but its poignancy is tangible), Regula Mühlemann’s dulcet Servilia (charming in her virtuous sentimentality), Tara Erraught’s blithe Annio and Adam Plachetka’s resonant Publio. Less happily, Villazón’s effortful strain hampers arias that require limpid finesse: ‘Del più sublime soglio’ is clumsily laboured; uneasy navigation of quick coloratura passages diminishes ‘Se all’impero’. The tussle between undue forcefulness and searing dramatic power is more persuasive in astute recitatives: the ramping tension when Tito has to decide whether or not to sign his friend’s death warrant (Act 2 scene 8) is compelling drama.

One of the drawbacks of the series is featherweight notes that resemble effusive press releases rather than expert essays. Nevertheless, the booklet presents Nézet-Séguin’s shrewd observation that ‘dramatic expression has nothing to do with the number of notes or whipped-up orchestration. It’s often just small details … but these open up new worlds of expression and emotion. That’s why we have to be so attentive in Mozart: because every single note is precious and important.’ This perspective is borne out by the Chamber Orchestra of Europe’s superb playing, conducted as intelligently as any of the most satisfying versions in the discography (to my reckoning, Gardiner, Hogwood and Mackerras). Moreover, its origin as a concert performance does not inhibit the imperative senses of theatrical flow and emotional momentum. The RIAS Chamber Choir play their valuable part to perfection, not least in the rapidly unfolding tensions of the Act 1 finale (magnificently done by all participants) and at the miraculous transition sprung from Vitellia’s penitent soliloquy directly into the wide-open public space of the amphitheatre setting for the final scenes – a moment bowdlerised by Jérémie Rhorer in his recent account but here conducted flawlessly by Nézet Séguin.