When that I was and a little tiny boy
  With hey, ho, the wind and the rain,
  A foolish thing was but a toy,
  For the rain it raineth every day.

  But when I came to man's estate,
  With hey, ho, the wind and the rain,
  'Gainst knaves and thieves men shut their gate,
  For the rain it raineth every day.

  But when I came, alas, to wive,
  With hey, ho, the wind and the rain,
  By swaggering could I never thrive,
  For the rain it raineth every day.

  But when I came unto my beds,
  With hey, ho, the wind and the rain,
  With toss-pots still 'had drunken heads,
  For the rain it raineth every day.

  A great while ago the world began,
  With hey, ho, the wind and the rain,
  But that's all one, our play is done,
  And we'll strive to please you every day.

(from Twelfth Night)

The genius of Twelfth Night is Feste, the most charming of all Shakespeare’s fools, and the only sane character in a wild play. Olivia has inherited this court jester from her father, and we sense throughout that Feste, an accomplished professional, has grown weary of his role. He carries his exhaustion with verve and wit, and always with an air of knowing all there is to know, not in any superior way but with a sweet melancholy. His truancy is forgiven by Olivia, and in recompense he attempts to charm her out of her prolonged mourning for her brother. Feste is benign throughout the play, and does not participate in the gulling of Malvolio until he enters the dark house as Sir Topas. Even there, he is instrumental in bringing about the steward’s release. A superb singer (his part was written for Robert Armin, who had an excellent voice), Feste keeps to a minor key: “Present mirth hath present laughter:/What’s to come is still unsure.” Though of Olivia’s household, he is welcome at the music-loving Orsino’s court, and gets Orsino right at one stroke:

Now the melancholy god protect thee, and the tailor make thy doublet of changeable taffeta, for they mind is a very opal. I would have men of such constancy put to sea, that their business might be everything and their intent everywhere, for that’s it that always makes a good voyage of nothing, Farewell. (II.iv.73-78)

The fool’s most revealing scene begins in Act III, and is shared with the equally charming Viola, who gently provokes him to meditate upon his craft: “A sentence is but a chev’ril glove to a good wit - how quickly the wrong side may be turned outward!” That may be Shakespeare’s playful admonition to himself, since the amiable Feste is one of his rare surrogates, and Feste is warning us to seek no moral coherence in Twelfth Night. Orsino, baffled by the sight of Viola and Sebastian together, utters a famous bewilderment:

One face, one voice, one habit, and two persons! A natural perspective, that is, and is not! (V.1.214-15)

In a useful gloss, Anne Barton calls this an optical illusion naturally produced, rather than resented by a disturbing perspective glass. The play’s central toy is Feste’s, when he sums up Malvolio’s ordeal: “And this the whirligig of time brings in his revenges.” Dr.Johnson said of “a natural perspective” that nature so puts on “a show, where shadows seem realities, where that which ‘is not’ appears like that which ‘is’.” That would seem contradictory in itself, unless time and nature merge into a Shakespearean identity, so that time’s whirligig then would become the same toy as the distorting glass. Imagine a distorting mirror whirling in circles like a top, and you could have the compound toy that Shakespeare created in Twelfth Night. All of the play’s characters, except the victimized Malvolio and Feste, are representations in that rotating glass.

At play’s end, Malvolio runs off stage shouting: “I’ll be reveng’d on the whole pack of you!” Everyone else exits to get married, except for Feste, who remains alone to sing Shakespeare’s most wistful song…

…Whether or not Shakespeare was revising a folk song, this is clearly Feste’s lyric farewell, and an epilogue to a wild performance, returning us to the wind and rain of every day. We hear Feste’s life story (and Shakespeare’s?) told in erotic and household terms. “A foolish thing” probably is the male member, ironically still “but a toy” in the man’s estate of knavery, marriage, ineffectual swaggering, drunken decline, and old age. “But that’s all one” is Feste’s beautiful sadness of acceptance, and the next afternoon’s performance will go on.

from Shakespeare: The Invention of the Human, by Harold Bloom

NOTE: This is one case where I’m sending it in both for the song, which is one of Shakespeare’s most charming, and for the criticism as well. Harold Bloom has nicely been described as the ‘current vestal virgin at the shrine of Shakespeare.’ Its certainly hard to think of anyone who has a greater reverence and exultation in Shalespeare. This is what hits you in his hufgely enjoyable new book Shakespeare: The Invention of the Human. Its idiosyncratic, enthusiastic, almost bonkers - but SO readable. Read it!