Comment by zahlman
14 hours ago
"Tetrachord" typically refers to a series of four notes separated by a perfect fourth, not simultaneous notes, coming out of the music theory of the ancient Greeks. Although that may not be the intended meaning here.
The quote is not calling a major chords a tetrachord; it's comparing major chords to the set of tetrachords (whatever the quoted person has in mind; the linked paper isn't immediately accessible to me), despite not being a member.
Well, that doesn't make any sense either, as major chords don't have any perfect fourths in them either, unless you count the interval between the fifth degree and the tonic in an inversion.
For the harmonic convention of chords based on stacked fourths, I've always heard it called "quartal" harmony, but my knowledge doesn't go very deep there.
In any case, wikipedia disagrees.
> In music theory, a tetrachord (Greek: τετράχορδoν; Latin: tetrachordum) is a series of four notes separated by three intervals
I think you misunderstood the comment you're replying to.
They meant (like Wikipedia says) that traditionally a tetrachord spans a perfect fourth (i.e., that's the interval between the first and last notes), not that it's a stack of perfect fourths.
As to the original point, any discussion about dissonance of chords is meaningless without mention of temperament: in the modern tuning system (equal temperament[1]) both major and minor triads are pretty dissonant, look at the thirds at the table in the section named "Comparison with just intonation" in that Wikipedia page.
We have been dealing with the tension between keeping thirds and fifths pleasant for centuries: very roughly, people used meantone temperaments[2] in the Renaissance (which had perfectly tuned thirds), then came the era of well temperament[3], and eventually we settled for the simpler equal temperament we use today with its nasty thirds (it has several other advantages, but "having pleasant major and minor triads" is not one of them).
[1] https://en.wikipedia.org/wiki/Equal_temperament
[2] https://en.wikipedia.org/wiki/Meantone_temperament
[3] https://en.wikipedia.org/wiki/Well_temperament