Sir John Falstaff's search for financial security through the love of a rich woman sets in motion the plot of one of Shakespeare's most glorious comedies. Entirely convinced of his own magnetic attraction, the fat knight makes his amorous target not one but two of the rich and merry wives of Windsor. Unfortunately for him, Mistresses Page and Ford are bosom pals. They compare notes - literally, these being the preposterous letters of love he addresses to them, in comically similar terms. They vow to punish him, and do so - to their satisfaction and our delight.

There have been many fine productions of The Merry Wives from the Royal Shakespeare Company. Gregory Doran recalls in a programme note - with evident delight, which I share - the one directed by Bill Alexander, an astonishing 20 years ago, which was set in the 1950s and saw the vengeful wives plotting Sir John's discomfiture while helmeted by salon hair dryers. Not until now, however, has there been a musical version, and we are lucky indeed that it has fallen to Mr Doran, who possesses a magical touch where entertainment is concerned, to direct it to a script of his own devising in which most of Shakespeare's lines remain intact.

He has assembled a cast - well, perhaps not to die for but, stopping just short of that, to see in action (at Stratford's main house, until February 10) at almost any price. Waddling in somewhat belatedly for an injured Desmond Barrit, Simon Callow - never an actor to underplay a role - seizes the part of Falstaff with customary vigour, at his best when suggesting the monumental conceit of the man but never overlooking his essential dignity, which is preserved throughout his vicissitudes. Making a virtue of necessity, Callow even managed on Press night to wring extra laughs from the role when he accidentally addressed by his real name the pathologically jealous Frank Ford (Alistair McGowan) who had gone to him disguised as a man called Brook, as part of a plot to test his wife's fidelity. Quick-thinking McGowan, at the joyful denouement of the drama, earned approval too, with a self-scripted line about Falstaff having almost rumbled him.

Dame Judi Dench gives a wonderfully affecting portrait of Mistress Quickly, the romantic 'fix-it' character who, since she sees good in everybody, even manages to discern some in her one-time wooer (for which read exploiter) Sir John. It matters little that she can't really sing, though Honeysuckle Villain - her regretful ditty concerning the knight - is given a suitably breathy delivery, before she ups the tempo, and makes off with Pistol, played as a Russell Brand lookalike by Brendan O'Hea. (Other members of Falstaff's retinue include the punkish Nym, played by Ian Conningham, complete with crest of bright pink hair, and a kilted Glaswegian Bardolph from Ian Pirie). Dame Judi can't do cartwheels either these days - but that does not stop her performing an impressive succession of them, through the use of a body double.

I had expected, I think, more rollicking amusement than the show provides - though the song Merry Wives, admirably led off by Mistresses Page (Haydn Gwynne) and Ford (Alexandra Gilbreath), develops into a merry hoe-down which comes to involve the whole company clattering away (in the manner of Stomp) on everything vaguely instrument-like that comes to hand. This is one of a richly varied set of numbers from composer Paul Englishby and lyricist Ranjit Bolt. Stand-outs include the lovely ballad Oh Anne, sung by the lovelorn Fenton (Martin Crewes) to his devoted Ann Page (Scarlett Strallen). Her efforts, incidentally, to fend of the rival suits of the absurdly foppish Abraham Slender (the excellent Simon Trinder) and the over-the-top Frenchman Dr Caius (Paul Chahidi) are not forgotten. This is a well-managed and good-looking version of a much-loved play in which little has been lost and a lot gained.