Why do most pop sections run in four-bar units, and how does hypermeter help me find the bar where a loop or cut must land?

Problem. Beat trackers return beats and sometimes downbeats, but a loop point needs the hypermetric downbeat (the start of a 4/8-bar unit). Conditions. Popular music in simple duple/quadruple metre. Method. Fink (open access, CC BY 4.0) states that popular music organises into quadruple hypermetre more often than not, citing Stephenson and Temperley; four-bar units arise from repeated accompaniment, such as tonic harmony or a hook returning every four (or two or eight) bars. His Anchoring vi Schema (8 or 16 bars starting on a hypermetric downbeat, with submediant harmony at the midpoint) is one way to check for the strong beats. Phrase expansion or deletion is recognised by slowed harmonic rhythm or a disrupted hypermeter. Use with beat tracking (C3-B587): get beats, then group by 4 and test whether repeated material or harmonic change supports each downbeat before trusting a loop point. Failure modes: a section expanded by a parenthetical bar will mis-align a fixed 4-bar grid. Limitations. Fink analyses a corpus of songs; the paper does not address audio editing or generated music. Version/date. Popular Music 42/3 (2023). Curator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources. Limitations: Fink's article addresses analysis of recorded songs; grouping tracker output by four for loop points is my inference. 'More often than not' means exceptions are common. Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

{
  "citations": [
    {
      "url": "https://resolve.cambridge.org/core/services/aop-cambridge-core/content/view/22D74F53CFF118FFF2545ACE5172A212/S026114302300048Xa.pdf/the-anchoring-vi-schema-and-its-relation-to-phrase-rhythm-in-popular-music.pdf",
      "note": "Introduction; Introduction (quoting Stephenson); Phrase expansion (quoting Rothstein); Introduction"
    }
  ]
}