Critics, scholars and biographers once damned Mozart’s last serious opera (composed almost simultaneously with Die Zauberflöte but performed at Prague three weeks earlier). Few of these estimable commentators had the opportunity or inclination to appreciate the virtues of opera seria. Nowadays it seems that anybody who respects the musico-dramatic merit of operas composed before 1780 will suffer no problems admiring Mozart’s finely crafted enlightenment opera. Metastasio’s libretto (adapted by Caterino Mazzolà) focuses on the poignant dilemmas of three formidable protagonists: the benevolent and well intentioned Emperor Tito, maligned by the hateful Vitellia, whose insatiable thirst for vengeance finds a gullible instrument in her youthful lover Sesto.

It is good to read René Jacobs’s passionate advocacy for Metastasio’s dramaturgy; he openly acknowledges where he has taken some liberties with Mozart’s score but it does not guarantee that all of his solutions are convincing, attractive or necessary. Most noteworthy elements in Jacobs’s direction could split opinion: the liberal application of pulling back the orchestra in the Overture’s opening bars is contrasted with sudden over-accelerations (contrived or revitalising?); elaborately ornamented piano solos or seemingly ‘improvised’ flourishes from the cello are inserted before some recitatives (intrusive absurdities or imaginative colour?); Mozart’s notation of rhythms is frequently interpreted in unpredictable and unconventional ways (reappraisals or mannerisms?); Mozart’s magnificent quintet at the end of Act 1 is far too rapid to be a sensible interpretation of the tempo marking Allegro assai (fully charged theatricality or losing the music’s potential impact?)

There are unequivocally good things on offer: Mark Padmore’s smooth-toned Tito has unforced purity, his arias are eminently civilised and his two accompanied recitatives make the Emperor’s anguish and inner conflict regarding his treasonous friend’s fate transparent. He brings agile coloratura and a sweet top A flat to ‘Se all’impero, amici Dei’. Alexandrina Pendatchanska’s dark timbre, dramatic conviction and ambitious ornaments in ‘Deh se piacer mi vuoi’ make her villainous Vitellia formidable (although the stilted shaping of the line ‘alletta ad ingannar’ seems unnatural). Bernarda Fink’s plangent contributions capture Sesto’s desperate struggle between honour and love.

Sir Charles Mackerras completes his slow-cooking cycle of Mozart’s seven mature operas with the Scottish Chamber Orchestra (most of them have been on Telarc but this is his first release for many years on DG). There are few Mozartians of Mackerras’s standard: every aria, ensemble, march, chorus and recitative is steeped in absorbing Mozartian rhetoric, colour, personality and style. There are no traces of artificiality or idiosyncrasy. Period brass and timpani lend precision and idiomatic colour, and the modern strings and woodwind are stirring, balanced and lyrical. From the first few minutes of the stirring yet immaculately judged overture, he delivers something special.

Rainer Trost’s voice has lost its youthful purity since his memorable Ferrando in John Eliot Gardiner’s Così fan tutte a little over a decade ago, but the acquisition of darkness and striking authority suits the dignity of his compassionate ‘Del più sublime soglio’. His richly textured coloratura and Mackerras’s flowing grandeur are marvellous companions in the opera’s jubilant final chorus (‘Tu, è ver, m’assolvi, Augusto’).

Hillevi Martinpelto’s seductive Vitellia makes Sesto’s obsession thoroughly convincing: ‘Deh, se piacer mi vuoi’ has the perfect synthesis of power, passion and purity (her ornamentation is every bit as courageous as any of Jacobs’s singers, but also fits smoothly with the harmony). She magnificently conveys Vitellia’s voyage from vulnerability to penitent heroism in ‘Ecco il punto’, and follows it with a radiant ‘Non più di fiori’ (few sopranos manage to get the audience to end up sympathising with Vitellia to this extent).

However, Magdalena Kozená’s Sesto steals the show. She is an outstanding Mozart singer; she sings her heart out in the dynamic accompanied recitative ‘Oh Dei, che smania è questa’ that leads into the quintet at the end of Act 1 (Mackerras and the SCO strings respond with stunning energy), and her arias are consistently marvellous.

Mackerras and Jacobs both provide fresh impetus to the least-regarded opera of Mozart’s maturity. If one must choose between them, the veteran pays richer dividends than the maverick.