Never was a middle-of-the-road star rating easier to apply. For every inspired event in the new Don Giovanni from Garsington Opera there’s a humdrum filler moment; for every kinetically interesting sequence there’s an interlude of stand-and-deliver stasis; for every magnificently sung aria there’s a wrong-’un.

The two unrelated Boyds, Douglas (conductor) and Michael (director), previously collaborated for Garsington back in 2016 on a successful Eugene Onegin, the production that first revealed Natalya Romaniw as a fully-fledged Tchaikovskian soprano. It proved to be a fine showcase for both of these creative gentlemen. This time round their fortunes are mixed, musically thanks to a major casting concern, dramatically because the direction of the singers is insufficiently detailed. Compared to Paul Curran’s brilliant micro-management of The Bartered Bride 24 hours earlier, Michael Boyd’s attention to character in Mozart’s dark comedy seems perfunctory. This is surprising from the distinguished erstwhile director of the Royal Shakespeare Company, but it may be that he's used to expecting greater autonomy and input from professional actors. Sometimes singers need greater support in the creation of their roles.

To take just one example: Jonathan McGovern, a company regular and last year’s Papageno at this address, sang a forthright, mellifluously expressive Don, vocally the libertine of Mozart’s imaginings but physically insufficiently magnetic. His laddish demeanour was more cock of the walk than of the bedroom: he strutted when he should have seduced, preened when he needed to pounce. When the baritone rocked back on his heels during "Là ci darem la mano", all the Don’s sexuality evaporated.

Still, he and his manservant Leporello, sung by David Ireland (an ENO Harewood Artist), formed a musically satisfying partnership and revelled in the opportunities afforded by Boyd and designer Tom Piper’s decision to use an open stage. The pair’s dominance of the wide acreage makes for a grungily energetic if unfocused production. It is set in a semi-abstract paintshop and cleverly uses violent art as an allegorical substitute for sexual aggression, with paint thrown at canvasses and masterworks desecrated by obscene daubs. The opera’s opening minutes are virtuosic, brilliant and breathtaking, but their impact is not sustained once the Commendatore (Paul Whelan, nicely controlled) has breathed his last.

Garsington’s Donna Anna, Camila Titinger, has so many prizes to her name that she must simply have been out of sorts on the production’s first night, but her poor intonation and vocal control did much to rattle the musical framework that Douglas Boyd and the Garsington Opera Orchestra had so carefully constructed. Yet how thrilling was the pit musicians' momentum during the urgent final scenes! Far more in sympathy was the Donna Elvira of Sky Ingram who, despite being locked into a production that offered her character scant levels of kindness (especially in the “gulling” scene that opens Act 2), scored a personal triumph. Tenor Trystan Llŷr Griffiths deservedly got to sing both Don Ottavio’s great arias and delivered them with passionate élan, while Mireille Asselin and Thomas Faulkner were excellent as the troubled lovers Zerlina and Masetto.

As a hybrid of brilliance and disappointment, then, this Don Giovanni is in a class of its own. Yet it is worth catching for the good bits. Mozart's final ensemble, “Questo è il fin di chi fa mal”, is omitted here as so often elsewhere too, which leaves the production devoid of a moral. In the circumstances, that is oddly fitting.