If music be the food of love play on,
Give me excess of it that surfeiting
The appetite may sicken and so die.
In Shakespeare's time women actors were not permitted on the stage. Their roles were usually played by boys or men who could do high pitched tones. You can imagine therefore the dramatic tension that can be created by a somewhat gender bending role, and what that can add to certain romantic situations.
So when a young lady, Viola, and her twin brother, Cesario, get shipwrecked, she washes up alone on the hostile shores of Illyria, where the Duke of Orsino does not allow women in court because he only has eyes for the Duchess. Adopting the guise of the brother she gains the Duke's trust, and he asks her to woo the Duchess in his name. Unfortunately, the Duchess has recently also lost her brother, and sworn off men for seven years.
The Duchess falls in love with Viola as a man, while Viola falls in love with the Duke as a woman, setting up a complicated romantic triangle. Meanwhile, Malvolio literally means ill will, we have music with Ben Kingsley as Feste the clown, and an attempt to mislead the melancholic Malvolio in the ways of love, and a mysterious anonymous message lending farcical elements. You wonder if Viola's brother might have miraculously survived the shipwreck.
In my opinion Imogen Stubbs does an excellent job doing double duty, and Helen Bonham Carter steals the show in every scene. Her facial expressions are priceless.
As a Shakespeare production I have to give Trevor Nunn top marks for delivering a beautiful setting, developing the tension very well, and for the license he takes with the scenes, I particularly like that the twins were a singing duo, and the bath scene. Ben Kingsley's experience and presence as a Shakesperean actor shows through in every scene.
Perhaps best considered as part of a trio of plays including As You Like It, with which it has the thematic similarity of a woman in disguise as a man, and Much Ado About Nothing, a romantic comedy set in Messina.
Twelfth night features the famous saying: Some are born great, some achieve greatness and some have greatness thrust upon them.
I consider this one of the best renditions of Shakespeare to screen, and if you get a chance, I particularly recommend you check out Zeffirellis Romeo and Juliet (Widescreen)
starring Olivia Hussey. Sublime.
I have also seen an earlier version of TN with Joan Plowright in the role of Viola, and Alec Guinnes as Malvolio. Unlike this modern version JP looks the sasme as either a man or a woman, and while she is a good actress, I estimate she may have been about 50 when playing the part, which is probably more suited to a woman in her early 20s like Imogen Stubbs. That version while quite good made me appreciate the dynamism of this one more. It's not just a great play, now it's a great movie.
I think you will love it and I hope this was helpful.