Looped harmonic progressions, like the Axis Progression, are a common occurrence in popular music. Yet despite their ubiquity, little empirical research has examined whether listeners actually perceive these repeating patterns as distinct harmonic entities when hearing music. This presentation addresses that gap by reporting on how timbre and musical training influence listeners ability to recognize looped harmonic progressions in ecologically valid popular-music contexts through three experiments.

I conducted three listening experiments using short excerpts of real songs ("ecologically valid stimuli") and matching tasks involving nine common four-chord progressions. Across all experiments (N = 285), participants with musical training consistently outperformed nonmusicians, though both groups performed quite poorly. Musicians rarely exceeded 50% accuracy, and nonmusicians often hovered near chance. The strongest performance occurred when participants began with MIDI stimuli and had to match them to ecologically valid stimuli, suggesting that reduced timbral complexity facilitates recognition of harmonic structure. Conversely, when both target and options were drawn from full ecologically valid stimuli, accuracy declined sharply. These results indicate that timbre and production parameters significantly mediate the perceptual accessibility of harmonic information in popular music.

With these results, I argue that rather than assuming harmony functions as a directly perceived structural concept. By considering looped harmonic progressions in an experimental context, this presentation connects empirical findings to the analysis of popular music harmony. The results suggest that what listeners attend to in popular music often lies beyond harmonic syntax, shaped instead by the interaction of timbre, texture, and production.