Incomplete repetition is a musical form

Musical form

The term musical form refers to the overall structure or plan of a piece of music, and it describes the layout of a composition as divided into sections...

 featuring two large sections

Section (music)

In music, a section is "a complete, but not independent musical idea". Types of sections include the introduction or intro, exposition, recapitulation, verse, chorus or refrain, conclusion, coda or outro, fadeout, bridge or interlude...

, the second being a partial or incomplete re-presentation or repetition

Repetition (music)

Repetition is important in music, where sounds or sequences are often repeated. One often stated idea is that repetition should be in balance with the initial statements and variations in a piece. It may be called restatement, such as the restatement of a theme...

 of the first. (Nettl 1956)

This form is used throughout the traditional Plains-Pueblo Native American music where the first section uses vocable

Vocable

In speech, a vocable is an utterance, term, or word that is capable of being spoken and recognized. A non-lexical vocable is used without semantic role or meaning, while structure of vocables is often considered apart from any meaning...

s and the second uses meaningful words or lyrics

Lyrics

Lyrics are a set of words that make up a song. The writer of lyrics is a lyricist or lyrist. The meaning of lyrics can either be explicit or implicit. Some lyrics are abstract, almost unintelligible, and, in such cases, their explication emphasizes form, articulation, meter, and symmetry of...

. Typical formal schemes include ABC, BC, AABC, and ABC and each section uses a tile type melodic contour. (ibid)

Source

• Nettl, Bruno (1956). Music in Primitive Culture. Harvard University Press