Don Giovanni, Royal Opera House, London

Don Giovanni, Royal Opera House, London

The new Don on the block is elegant, svelte, small but perfectly formed. Great pecs. He is Simon Keenlyside, leading the second cast into Fancesca Zambello's over-populated but improving production of Mozart's Don Giovanni. It doesn't look any better – Maria Bjornson's designs go to the wall at great expense – but the central relationships seem sharper now, there's been a shift of emphasis, of balance, since Bryn Terfel's all-pervasive brute of a Don went below. It's interesting that our final glimpse of him was in inglorious isolation. Our final glimpse of Keenlyside finds him carrying off a naked woman. Shift of emphasis, indeed.

But there's something else, something even more key to the success, the pace, the energy, and dynamism of the evening – and that's the conducting of Sir Charles Mackerras. Where Sir Colin Davis was grandly authoritative, Mackerras is lethally incisive. The opening gesture of the overture, cut to the bone, precipitous (no boomingly portentous overhang of string basses for Sir Charles) is shockingly abrupt, the ensuing allegro instantly conveying the reckless dash of the narrative. So many women, so little time.

I honestly cannot remember when I last heard a better conducted Don Giovanni in the theatre. Rhythm, articulation, fluency and beauty of line – the playing was quite superb – but above all an acute sense of the score's earthy buffo elements. The accompaniment to Leporello's so-called "catalogue aria" was a case in point: capricious to a fault, cavorting bassoons lending an air of roguish parody to Leporello's tally of the Don's conquests.

Ildebrando D'Arcangelo is a complete knock-out as Leporello – charming, funny, sexy, but pointedly in touch with his emotions in ways that his master can never be. What a difference a native Italian speaker makes in the role. Not that Simon Keenlyside's Don is found wanting in that respect. Physically and vocally it's a much more discreet, less domineering performance than Terfel's – Keenlyside's voice, though classy, lacks charisma – but in some ways his elegant understatement, the touch of feyness in the demeanour, is a more menacing way to go with the role. For one thing, it throws the women's blind fixation on him into even greater relief.

They were all good. Especially Ana Maria Martinez as Donna Elvira – a real star. This production might be dubbed "Elvira Get Your Gun" after the lady for whom a musket is now the perfect accessary to her soiled wedding dress. Martinez communicates with humour and temperament the irrationality of one for whom love and hate are now indivisible. "Mi tradi" is the music of madness, all breathless, palpitating rhythm and distracted vocal runs – and that's how she characterised it.

Christine Goerke's Donna Anna was impressive, too: poised, imperious, failing to keep her powder dry only fleetingly in the Queen-of-the-Night-like coloratura of "Non mi dir". John Mark Ainsley (Don Ottavio) has lost some of his vocal lustre of late: there are problems over the break, chest and head tones aren't complementing each other as they might. Still, the illusion of beauty is in the musicality and there was plenty of that on display.

A cracking evening for Mozart, then. Fire and water make for a steamy denouement in the Don's bathhouse but Mackerras (with trumpets and hard-sticked drums blazing) and his cast have the temperature soaring long before then.

To 28 Feb (020-7304 4000)