Rhyme schemes and sound effects
Rhyme is an important tool in the poet's toolbox. Traditional poetry forms such as sonnets often use rhyme in specific patterns. But even if writing free verse, rhyme may be used to create desired effects.
Why rhyme?
There are many reasons why poets might choose to use rhyme.
To give pleasure. Rhyme, done well, is pleasing to the ear. It adds a musical element to the poem, and creates a feeling of "rightness," of pieces fitting together. It also makes a poem easier to memorize, since the rhyme echoes in the reader's mind afterward, like a melody.
To deepen meaning. Rhyming two or more words draws attention to them and connects them in the reader's mind.
To strengthen form. In many traditional forms, a regular pattern of rhymes are at the ends of the lines. This means that even if the poem is being read out loud, listeners can easily hear where the lines end, can hear the shape of the poem.