It's a bold man who tries to improve Mozart, but Richard Jones did not get where he is today – that is, in the top drawer of the cabinet of curiosities marked Go-to Opera Directors – without having the courage of his convictions. His new Don Giovanni for English National Opera veers erratically, however, from the mould-breaking to the mundane.

The seducer's Spanish stamping ground is more Ibis hotel than Iberia, drear walls and doors in camouflage shades moving and being moved through restlessly, in Paul Steinberg's design, grimly lit by Mimi Jordan Sherin. The libidinous don and his long-suffering man servant Leporello duck and dive in the matching satin suits of crooners, and the many women, aggrieved, bereaved or deceived, strut in Vivienne Westwood-style Baroque or standard issue English National Opera chorus smocks, costume design by Nicky Gillibrand.

But it's the music that counts, of course, and the plot, which Jones unflinchingly rewrites, turning the denouement on its head, ingeniously and plausibly – but confusingly for any newcomer to this mainstay of the operatic repertoire. Suffice to say that the Don does not get his comeuppance, despite what the music, or the librettist, say.

Christopher Purves in the title role is curiously underpowered, sometimes employing that crooner's diffidence, sometimes nearer to speech than song, so it is no wonder that his jilted Donna Elvira (Christine Rice) is at demonic screaming pitch. Jones's inventiveness is on surer ground that in the final scene when, as the curtain goes up, he suggests that Donna Anna (the American soprano Caitlyn Lynch, making her ENO debut) has instigated the very seduction of which she then complains.

Allan Clayton as Donna Anna's patient betrothed, Don Ottavio, was loudly and rightly hailed on first night for his two arias beautifully sung, and there is a great performance from Nicholas Crawley as the often insignificant or just plain irritating Masetto, side-lined husband of the don's latest target. His pain and frustration, when thwarted by power, money and class, are among the few things in this production to ring true. James Creswell is powerful as the slaughtered and then ghostly Commendatore, and Mary Bevan as Masetto's bride Zerlina is pitch perfect, as always.

Clive Bayley is on stupendous form as Leporello, his big bass voice and comic timing giving the whole affair a boost, not least for what will surely prove to be the best wig gag of the operatic year. But Jones should be ashamed of landing this able actor with a tired old cliche like representing Germany with a click of the heels. There is, elsewhere, some quite nasty ageism too, which is odd in a man of 63.

After the ponderous conducting by Semyon Bychkov of the Royal Opera House's own current Mozart opera, Così Fan Tutte, round the corner at the Royal Opera House, it was a treat and a relief to hear ENO's own Mark Wigglesworth getting tempi and colour just right, a really satisfying job, which makes his departure soon all the sadder.

This new Don Giovanni is a co-production with Theater Basel, an example of the sensible, cost-effective sharing of shows with other companies. It is that sort of measure that the new artistic director of ENO, Daniel Kramer, will be considering, for sure, as the company looks at its future at the start of a new season.

It may not be in the same league as Jones's two recent big hits for ENO, The Mastersingers of Nuremberg and The Girl of the Golden West, but, in the end, the music is indestructible. So he's a bold man, yes; it's just that, happily, Wolfgang Amadeus Mozart is bolder.