The structural part of a poem known as the _______ is any switch in the poem's progression that takes it on a new track.stanzarefrainmetershift

The correct answer is shift.

In the context of poetry, a shift refers to a change in the structure, tone, or theme of a poem. It often serves to provide a new direction in the narrative or emotional landscape of the piece. Shifts can occur through various methods, such as a change in diction, imagery, or even from one stanza to another. This dynamic can help maintain a reader's interest and can create tension or resolution, influencing how the message or emotional undertone is perceived.

Recognizing shifts within a poem can offer deeper insight into the poet's intentions and the overall meaning of the work. Often, these shifts highlight pivotal moments or transitions that are crucial in understanding the evolution of the poem's theme or sentiment. In literary analysis, identifying these shifts is essential for fully interpreting a poem's structure and emotional impact.