Eat, drink and be ... murdered. Such appears to be the pattern for villainy, to judge from two great works brought to Oxford this week by Welsh National Opera.

First, we had the odious Baron Scarpia - bumper of wine in one hand, carving knife in the other - as he prepared to ravish the heroine of Tosca. He was soon to find that blade had another use.

Then we saw Don Giovanni - "an extremely licentious young gentleman," as the cast list describes him - enjoying a similar solo banquet, before the animated statue of one of his victims, the Commendatore, arrives to join him.

The last time I saw the WNO's production of Mozart's opera, in 2003, the part of the murdered Commendatore was played by the Oxford-based baritone Christopher Purves, who has moved up the ranks to play the title role itself - and an excellent job he makes of it.

Aside from the quality of his singing perfect in tone and diction - he offers a performance notable for the quality of his acting. Against all the odds, he even manages to present a sympathetic side to the dirty don's character.

This is, of course, as Mozart and his librettist Lorenzo da Ponte would have wished - as the use of the word 'mischievous' suggests. But to the modern audience, the crimes that Don Giovanni commits - he is both a murderer and a serial rapist - are much more than mischief.

The action begins after he has attempted to force himself upon the virtuous Donna Anna - Geraldine McGreevy reprising the role she sang so successfuly here three years ago. As he attempts to make his escape, he is cornered by her father, the Commendatore (Jonathan May) whom he cold-heartedly butchers.

Anna and her ardent swain Don Ottavio - a superb performance from tenor Matthew Beale - then pledge their revenge on the wicked aristocrat. They are joined in their campaign by Donna Elvira (Elizabeth Atherton), an abandoned lover of the Don's who, it turns out, still has a soft spot for him.

Even as they plot his downfall, however, he continues in his wicked ways - even wresting peasant bride Zerlina (Elizabeth Donovan) from her fianc Masetto (Owen Webb) on her wedding day.

Throughout, he relies on the support of his increasingly disenchanted servant Leporello (Robert Poulton). His 'Catalogue Aria', listing the extent of his master's conquests - 1,003 in Spain alone - is, as ever, one of the highlights of the evening.

The opera, under conductor Michal Klauza, will be on again tonight. Tomorrow, WNO performs Tchaikovsky's Mazepa.