Joyce DiDonato fell and supposedly sprained her ankle during Act 1 of the first night of Covent Garden’s July 2009 revival of their Leiser/Caurier/Fenouillat Barber. She carried on in that performance using a stick. It transpired that her leg was broken. For subsequent performances she was not replaced but performed from a wheelchair, careering along the forestage in front of the set. Then, as if truly to validate Dr Johnson’s dictionary definition of opera in these islands as “exotic and irrational entertainment”, the result was filmed and put out on DVD.

Let’s go with the madness. Antonio Pappano’s conducting brings back the genuine Italian frisson of sprung rhythms, banda-like colour and prominence of wind and brass, and real tension (but lack of fake hurry) in crescendos.

The singing here, and its ornamentation, operates on a high level indeed, much aided in naturalness by the conducting. And in Juan Diego Flórez’s hands, Almaviva’s “Cessa di più resistere” for once holds up the action to some purpose.

The stage production is a highly coloured, non-specific, malleable event which could have got more out of this rather special cast. With this particular Rosina on wheels, it’s actually only her getting onstage that jars a little. Throughout, DiDonato gives more than her all – indeed, her emotional and physical violence during the storm might have had friends and nurses worrying in the wings. The stage directors seem to have concentrated their work on interesting line readings and avoiding this opera’s rich historical trough of comic clichés. Their classy baddies (Corbelli and Furlanetto) find new ways of physicalising their looniness; Rhys-Davies similarly is an unhackneyed Berta (and the aria, again in closest collaboration with the pit, has the natural “swing” of a musical hit). Pietro Spagnoli presents himself as a good age for Figaro (worldly-wise enough to watch and comment rather than try too hard himself), while Flórez lets us enjoy his drunken vet and music-master without overpointing their humour. All in all, the evening is a musical triumph and one that is at least diverting to look at.