Bound verse refers to a poem that adheres to specific formal constraints, such as:
* Meter: A regular pattern of stressed and unstressed syllables.
* Rhyme scheme: A pattern of rhyming words.
* Stanza form: A specific structure for each verse.
However, rhyme is not a requirement for bound verse. Many famous bound verse poems, such as sonnets and villanelles, do not rhyme.
Here's an example:
Sonnet 18 by William Shakespeare
> Shall I compare thee to a summer's day?
> Thou art more lovely and more temperate:
> Rough winds do shake the darling buds of May,
> And summer's lease hath all too short a date:
>
> Sometime too hot the eye of heaven shines,
> And often is his gold complexion dimmed;
> And every fair from fair sometime declines,
> By chance or nature's changing course untrimmed;
>
> But thy eternal summer shall not fade,
> Nor lose possession of that fair thou ow'st;
> Nor shall Death brag thou wander'st in his shade,
> When in eternal lines to time thou grow'st:
>
> So long as men can breathe or eyes can see,
> So long lives this, and this gives life to thee.
This sonnet follows a specific meter (iambic pentameter) and stanza form (14 lines in three quatrains and a couplet), but it does not rhyme.
Therefore, while rhyme is a common feature of many bound verse poems, it's not an essential element.