The Iambic pentameter reference article from the English Wikipedia on 24-Apr-2004
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Iambic pentameter

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Iambic pentameter is a meter in poetry, consisting of an unrhymed line with five iambs or feet (hence pentameter), felt by many to be the most powerful of all metrical forms in English poetry. William Shakespeare excelled in the use of iambic pentameter (as in his famous Sonnet XVIII, beginning "Shall I compare thee to a summer's day"). And consider this from Christopher Marlowe's "Dr Faustus":

Was this the face that launch'd a thousand ships
And burnt the topless towers of Ilium?

When read aloud, such verse naturally follows a beat. Many feel the success of iambic pentameters is related to its sounding like a human heartbeat at rest. In written form it looks like this:

da-dum da-dum da-dum da-dum da-dum
(weak STRONG / weak STRONG / weak STRONG / weak STRONG / weak STRONG)


So Marlowe's work would follow the pattern:

Was-this the-face that-launch'd a-thou sand-ships
And-burnt the-top less-tow ers-of Il-ium?

There is some debate over whether works such as Shakespeare's and Marlowe's were originally performed with this rhythm prominent, or whether it was disguised by the patterns of normal speech as is common today.

Example

The following is quoted from Tennyson's Ulysses (forward slashes have been inserted to separate the feet):
'Tis not / too late / to seek / a ne/wer world.
Push off,/ and sit/ting well/ in or/der smite
The soun/ding fur/rows; for/ my pur/pose holds
To sail/ beyond/ the sun/set, and/ the baths
Of all/ the wes/tern stars,/ until/ I die.
It may/ be that/ the gulfs/ will wash/ us down;
It may/ be we/ shall touch/ the Hap/py Isles,
And see/ the great/ Achil/les, whom/ we knew.
Though much/ is ta/ken, much/ abides;/ and though
We are/ not now/ that strength/ which in/ old days
Moved earth/ and heaven,/ that which/ we are,/ we are -
One e/qual tem/per of/ hero/ic hearts,
Made weak/ by time/ and fate,/ but strong/ in will
To strive,/ to seek,/ to find,/ and not/ to yield.