Interesting analysis. Some observations:

- Ultimate Guitar isn't exactly known for the sterling quality of its transcriptions. Teenage me submitted at least a few tabs that were clearly incorrect that still got 4 and 5 star ratings. Amateur guitarists are also infamously bad at figuring out voicings and extensions so something like a 9 might end up as a maj7 or just a triad. Adult me checks Songsterr first then uses his ear to figure out what's _really_ going on when I run across incorrect parts in the tablature.

- Some genres of music like downtuned metal are largely monophonic and instead rely on quick melodic movement or drone-y background guitars to imply harmony. This data set doesn't seem to account for this.

- There's no way that power chords only account for single-digit percentages of chords in rock, metal, and punk. There are albums that have been certified Platinum that are 90% power chords (technically power intervals, I suppose).