I analyzed chord progressions in 680k songs

Data source and methodological flaws

• Many see Ultimate Guitar as a poor-quality, highly simplified, crowd-sourced dataset; wrong chords, missing extensions, and “pro” versions behind a paywall.
• Chords are taken as written, so triads often stand in for 7ths/9ths/etc. and capo usage is ignored, inflating G, C, D, etc.
• The original dataset collapses repeated chords (e.g., C–C–G → C–G), which removes structural information crucial for forms like 12‑bar blues.
• Some argue the analysis is only valid for “UG-style chord sheets,” not for recorded music as actually performed.

Chords vs chord progressions; absolute vs relative

• Multiple commenters note the article mostly counts chord types rather than analyzing progressions, contrary to the title.
• Several argue proper analysis should normalize songs by key and use Roman numerals (I–V–vi–IV, ii–V–I, etc.) to uncover true harmonic patterns.
• Using absolute chords (G, D, etc.) is compared to counting raw letters instead of language structure; music perception depends on relationships, not absolute pitch names.

Genre-specific anomalies

• Strong skepticism about results like power chords being ~5–6% of metal and punk chords; players report those genres are overwhelmingly power-chord based.
• Jazz players dispute claims that major triads dominate and that keys like G and D are most common; they’d expect Bb/Eb/F and far more 7th chords.
• Some suggest UG guitar simplifications and genre biases (guitar-centric jazz, simplified rock/metal) explain these mismatches.

Music complexity and history

• Debate over whether modern music is “simpler”: some point out earlier eras had plenty of simple, disposable music too; we mostly remember the curated 10% that survived.
• Others note that chord-count complexity misses other dimensions (rhythm, arrangement, motivic development).

Music theory nitpicks and clarifications

• Discussion over terminology: interval vs dyad, triad, how to talk about distances between pitches.
• Explanations of Roman numeral analysis, common progressions (I–IV–V, ii–V–I, I–V–vi–IV), and why these better capture harmonic function.

Alternative analyses and tools

• Several recommend Hooktheory and other projects that already analyze normalized chord progressions and trends across songs.
• Some link to more focused academic work (e.g., harmonic studies of metal subgenres) as better examples of large-scale progression analysis.