Alliteration is the repetition of consonants and vowel sounds in consecutive words.
Alliteration using the same consonants in consecutive words is called consonance. Using the same vowel sounds consecutively is called Assonance.
"lady lounges lazily" is both alliteration and consonance
Example:
In cliches: sweet smell of success, a dime a dozen, bigger and better, jump for joy
Wordsworth: And sings a solitary song That whistles in the wind.
Repeating the same consonants in the beginning or consonant pairs within a series of words in the same line is called alliteration
A famous example is to be found in the two lines by Tennyson:
The moan of doves in immemorial elms,
And murmuring of innumerable bees.
Some poets used alliteration instead of rhyme as the similar sounds made in assonance and consonance can mimic the sounds of rhyme; in Beowulf there are three alliterations in every line. For example:
Now Beowulf bode in the burg of the Scyldings, Leader beloved, and long he ruled In fame with all folk since his father had gone . . .
Edwin Markham's "Lincoln, the Man of the People" is in unrhymed blank verse, but there are many lines as alliterative as:
She left the Heaven of Heroes and came down To make a man to meet the mortal need A man to match the mountains and the sea The friendly welcome of the wayside well
Robert Frost's "The Death of the Hired Man" begins:
Mary sat musing on the lamp-flame at the table
Waiting for Warren. When she heard his step. . . .
Alliteration of the letter 'm' is immediately apparent in Mary sat musing as they are the first letters of the poem and the letter 'w' in Waiting for Waren. When. But the more subtle consonance of lamp-flame can give the impression of faint rhymes.
Alliteration, like rhyme can aid in memory. Using alliteration helps us remember things in phrases such as: "sink or swim," "do or die," "fuss and feathers," "the more the merrier," "watchful waiting," "poor but proud," "hale and hearty," "green as grass," "live and learn," "money makes the mare go."
While alliteration is the recurrence of single letter-sounds, refrains are another kind of repetition that can add a rhythm to a poem, examples seen in Shakespeare's "With a hey and a ho and a hey nonino" or Rudyard Kipling's:
For it's Tommy this, an' Tommy that, an' " Chuck him out, the brute!
But it's "Savior of 'is country" when the guns begin to shoot.
Demonstrate the use of refrains that are closely related to alliteration. One may even use alliterated refrain lines for an extra beat
Excellent use of repetition occurs through the whole of Rudyard Kipling's "Tommy" "Danny Deever" and Alfred Noyes's "The Barrel-Organ" especially in such lines as:
Come down to Kew in lilac-time, in lilac-time, in lilac-time;
Come down to Kew in lilac-time (it isn't far from London!)
And you shall wander hand in hand with love in summer's wonderland;
Come down to Kew in lilac-time (it isn't far from London!)
Adding your comment:
Someone left a comment on one of my poems recently about my alliteration being "accidental". I informed them that it was quite on purpose and that I am notorious for it. 
Good column, Poet. 
