[jdontillman]

Sorry, but I have to say that none of this will make a particle of sense to someone who would be asking such a question.

A rudimentary question is a wonderful an opportunity to distill everything down to a simple understandable concept.

Here's how I would do it:

---

Western music is based on simple frequency ratios. 2:1 is so basic that we call it the same note, but an octave up.

Three pitches with ratios 4:5:6 make a major chord. These are the simplest possible ratios within an octave, so a major chord is the most basic chord, and all other chords are derived from that

[mrob]

>Western music is based on simple frequency ratios.

Western music is based on simple frequency ratios, played by instruments with harmonic timbres (meaning that when you decompose the sound of a single note into sine waves using a Fourier transform, the frequencies of the sine waves are all integer multiples of the lowest frequency sine wave).

This is true for wind and string instruments, but not true with tuned percussion unless you go to special effort to shape the instrument to make it so (as is done by bell makers). Musical styles that use inharmonic timbres, e.g. Indonesian gamelan music, need different tuning to sound best.

And this also happens in Western music. Piano is technically tuned percussion, and the sound of a piano is slightly inharmonic. Pianos are tuned with stretched octave to compensate:

https://en.wikipedia.org/wiki/Stretched_tuning

[jdontillman]

That's all very interesting...

But the harmonic or inharmonic content of the instrument does not address the original question.

And it leads to confusion; putting your first and last sentences together implies that a piano is not a western musical instrument. We know that's not true.

[mrob]

Piano timbre is approximately harmonic. The inharmonicity is subtle enough that you can ignore it and it will still sound okay. Same is true with plucked string instruments. You're still using Western music theory.

[jdontillman]

Yes, of course. I've tuned pianos, so I'm not disagreeing with that.

I'm just struck by the zenlike simplicity of the original question, "What is a Major Chord?", compared to the random bits of technical jibber-jabber that would confuse the hell out of a poor soul who would dare to ask such a question, both in the linked blog post, and the discussion here.

[jefftk]

The motivating question, which I quote at the beginning, was actually: what is a chord? what is a major chord? what is a note? what is a first/fourth/fifth note? is there a 65th note? what is a scale? what is a major scale? what does it mean that a note is of a scale? what does it mean that a chord uses a note? is there a difference between a chord using a note of a scale and not of a scale?

I picked one of them for the title of my post, but I'm trying to answer them all.

[jdontillman]

As a concrete example to my simple explanation, consider the bugle.

A bugle has no valves, it can only play the natural harmonics of the horn, as determined by lip pressure.

x3, x4, x5, and x6

Thus the ratios of the available pitches are 3:4:5:6.

That's a major chord (with the "fifth" down below).

All your iconic bugle calls ("Taps", "Reveille", etc.) are the notes of a major chord.