Like the Chilean tenor Ramón Vinay, Plácido Domingo has spread his repertoire from the weightier Italian roles – Verdi, Puccini, verismo – to 19th-century France (Bizet, Gounod, Saint-Säens, Offenbach), Russia (Tchaikovsky) and Wagner (Siegmund, Tristan, Parsifal, Lohengrin). He has, also like his predecessor, entered the baritone Fach with a recording of Rossini’s Figaro, a TV film of Rigoletto and – in Berlin, Milan, New York, London and Madrid – Boccanegra onstage, a role with which he once talked of ending his career.

We should cut to the chase. Domingo (as stage director Elijah Moshinsky comments in one of the release’s supporting interviews) does not sing Simon Boccanegra as a tenor, or as a baritone, but as Plácido Domingo. No vocal Tarnhelm has suddenly magicked a different-sounding timbre for this voice: here is, simply, Domingo singing – and evidently enjoying singing – a part that’s lower down. You may argue that this undersells, or even traduces, the two great no-tenors-allowed confrontations of this opera – the duets with Fiesco (Ferrucio Furlanetto) in the Prologue and Act 3 – but Domingo’s age and experience make up a little for the loss of lower sonorities. And the bigger difference in the voices here permits a greater antagonism of the characters and clarity of text. Elsewhere, the statesman in Domingo’s character makes much of the Council Chamber scene. That, and Verdi’s enjoyment of a newer, more pungent brass style, look forward even more than usual to Otello.

What we might here cheekily call the supporting cast are strong – Furlanetto and Calleja’s Adorno moving and Summers (a Boccanegra himself) experienced and wily as the Doge’s adversary Paolo. Poplavskaya – seemingly everywhere now in bigger Verdis – tends to frown a lot but has the height and stature of both figure and voice. The present DVD release, directed by Sue Judd for the BBC and speedily assembled from three Covent Garden performances last July, does not have to be Beckmesser-marked up in a comparative list of small-screen Boccanegras. It may be best viewed as a tribute to a singer’s achievement; a focus that should be shared here with the Royal Opera’s music director and his orchestra and chorus, the epitome of style and polish in this repertoire.