One modern adaptation is Twelfth Night, or what you will; directed by Trevor Nunn, and starring Helena Bonham Carter, Imogen Stubbs, and Ben Kingsley.

"O, mistress mine, where are you roaming?

O, stay and hear, your true love's coming,

That can sing both high and low." (II.iii.39-41)

Trevor Nunn decided to add this explanatory scene at the beginning, to explain the siblings' relationship and show the similarities of their features. Feste narrates.
"Once upon Twelfth Night, or what you will, aboard a ship bound home to Messeline, the festive company dressed for masquerade and singing songs each other to amuse, delight above the rest in two young twins."

The subsequent scene shows the shipwreck and landing in Illyria.

Viola becomes a boy:

"Conceal me what I am; and be my aid

For such designs as, haply, shall become

The form of my intent. I'll serve this duke."

The lovesick (and somewhat pathetic) Duke Orsino:

"If music be the food of love, play on;

Give me excess of it, that surfeiting

The appetite may sicken and so die." (I.i.1-3)

The mourning (we think) Countess Olivia:

"The element itself, till seven years' heat, 
Shall not behold her face at ample view; 
But like a cloistress she will veilèd walk, 
And water once a-day her chamber round 
With eye-offending brine: all this to season 
A brother's dead love, which she would keep fresh 
And lasting in her sad remembrance." (I.i.25-31)

Seven years becomes a few short weeks:

Our 'man' Cesario captures the fancy of the Countess while wooing on the Duke's behalf.

"Disguise, I see, thou art a wickedness

Wherein the pregnant enemy does much." (II.ii.27-28)

On another side, the Three Stooges plot revenge against "a time-pleaser" (II.iii.148).

"Be not afraid of greatness," writes Maria in Olivia's hand. "Some are born great, some achieve greatness, and some have greatness thrust upon 'em" (II.v.143-145).

Hilarity ensues as Malvolio acts on Maria's letter, and Sebastian appears and is mistaken for Cesario.

Antonio, mistaking Cesario for Sebastian, inadvertently gives Cesario hope that her brother lives.

"Prove true, imagination, O, prove true,

That I, dear brother, be now ta'en for you!" (III.iv.375-376)

Olivia makes the same mistake and convinces Sebastian to marry her, causing an awkward moment when Cesario and the Duke arrive, Andrew Aguecheek accuses Cesario of giving him a "bloody coxcomb" (V.i.190).

Sebastian appears, and the world makes sense once again.

The Duke, bereft of any chance for Olivia, makes the better choice and proposes to Viola. She, of course, accepts.

"Home"