A musical form that consists of one section repeated many times. Most commonly, the melody remains recognizable in each section, and the underlying harmonic structure remains basically the same, but big changes in rhythm, tempo, texture, or timbre keep each section sounding fresh and interesting is:.

Variations.

Explanation:

'Variation' is demonstrated as the formal musical form or technique that comprises of repetition of one specific section for a repeated number of times in an altered manner. The melody continues to be recognizable in each part, the elemental harmonic structure also remains the same but the considerable changes are observed in the 'rhythm, texture, tempo, or the timbre' that helps each section to operate in a freshly as well as interestingly. For Example; a ground bass. Therefore, 'variation' is the answer.