Formal or fixed verse takes many different forms, but since
the advent of free verse it refers especially to
poetry with intentional, regular rhymes and rhythm or meter that
enhance the sonic or musical effects of language.
Meter is "the beat" or rhythmic structure of lines in a poem. The most familiar metric line for English speakers is iambic pentameter, found in Shakespeare's plays and the blank or heroic verse of John Milton’s epic Paradise Lost, and other formal poems and classical English drama. (Examples below.)
Rhyme is repetition (in English) of vowel and consonant sounds, usually at the end of a line, as in the rhyming couplet (2-line unit) that concludes Shakespeare’s Sonnet 29:
For thy sweet love remembered such wealth brings
That then I scorn to change my state with kings.
Besides end-rhyme, these lines'
iambic pentameter—each line has five 2-stroke “feet”
with an unstressed syllable followed by a stressed syllable (think of "feet" as
"steps," like in a dance):
for THY sweet LOVE reMEMbered SUCH wealth BRINGS
that THEN i SCORN to CHANGE my STATE with KINGS.
(No one really speaks the poem in a perfectly sing-song way, but the lines' formal regularity aids memorization and adds order and beauty.)
Other essential terms for formal verse:
Stanzas (Oxford English Dictionary): A group of lines of verse . . . arranged according to a definite scheme which regulates the number of lines, the metre, and (in rhymed poetry) the sequence of rhymes; normally forming a division of a song or poem consisting of a series of such groups constructed according to the same scheme.
Common types of stanzas: quatrain (4 lines), couplet (2 lines), triplet (3 lines).
Prosody or the study of verse meters considers many varieties of metric feet (e.g., iamb, trochee, spondee) and lines (pentameter, tetrameter, trimester), as well as stanza units of lines including couplet, triplet, quatrain, sestet, octet, which may appear in countless poetic genres such as ballad, sonnet, ode, villanelle, rondeau, etc.
Such units may appear more technical and forbidding than they are; many such forms thrive in popular songs, where even if you don’t know the terms you can tell when a line has too many syllables or feet, or when a rhyme sounds forced or wrong.
Rhymes too have variants such as half-rhymes, sight-rhymes, and internal rhymes instead of end-rhymes.
Historic Background for Formal Verse
Fixed verse's many forms are the work of many days for devoted students, but why did these forms dominate poetry of the past?—especially since free vers is the assumed form of more recent or modern poetry?
The short answer is poetry's association with music and song. Like songs even today, poetry in the past was experienced not so much on the page but more in person, heard aloud, in sung or spoken forms, and the poet or singer was expected to know poetry by memory, just as singers at a concert or actors on a stage are expected to memorize their lines.
In brief, meter and rhyme are MNEMONIC or MEMORY-REINFORCING: regular rhythm and rhyme cue the memory to what comes next.
As easy proof, many students sooner or later have to memorize and recite a poem or a passage from a play. Almost invariably the poem assigned will be rhymed or metrical or both.
In contrast, the exact form of free verse is comparatively hard to remember and recite. In contrast to the spoken or oral tradition that underlies formal poetry, free verse appeared in the mid-1800s simultaneous with the industrial expansion of printing that made books and magazines available to a growing class of literate people.
Formal verse has revived somewhat in the past generation with the New Formalism movement.
Blank or Heroic Verse in English
Oxford English Dictionary. blank verse n. verse without rhyme; esp. the iambic pentameter or unrhymed heroic, the regular measure of English dramatic and epic poetry . . .
Examples of Blank or Heroic Verse (i.e. unrhymed iambic pentameter)
John Milton, Paradise Lost (1674)—opening lines:
Of Man's First Disobedience, and the Fruit
(Milton referred to this form as "English heroic verse without rhyme," but the 17th century also referred to it as "blank verse.")
Other popular examples of "heroic" or "blank verse" (unrhymed iambic pentameter):
Most parts of Shakespeare's plays are written in blank verse, e.g. . . .
from Shakespeare's Romeo and Juliet (ca. 1595), Act 2, Scene 2
Romeo: Lady, by yonder blessed moon I vow
Juliet: O, swear not by the moon, the
Ulysses (1833, 1842) by Alfred, Lord Tennyson
. . . 'Tis not too late to seek a newer world.
Harlem Dancer (1922) by Claude McKay
Applauding youths laughed with young
Examples of formal or fixed verse: