Triads > [expansion] vs [extension]..?

so it occurred to me:

triads are just pure chords {1, m3/3, 5}

and what we typically call "chords" are triads with octaves thrown in; give or take other scale degrees.

so I started thinking of the latter as

"expanded triads"

but it occurs to me:

that might be referring to throwing in other scale degrees

like would a em7 {1, 5, m3, m7} be an "expanded triad"?

are the words expanded and extended used in relation to triads or chords?

and if so what's the connotation thereof?

does the term differ...

depending on if it's just octaves of the 1, m3/3, 5...

or other scale degrees added or substituted?

This tutorial covers the basics of chord theory.  It will answer most of your questions.

https://www.guitartricks.com/tutorial/148/

Directly responding.

"like would a em7 {1, 5, m3, m7} be an "expanded triad"?" "are the words expanded and extended used in relation to triads or chords?"

Yes, extended harmony chords is the commonly used term.  Some musicians reserve the term for chord tones beyond the 7th, starting with the 9th, including the 11th, 13th.  I prefer to call anything beyond 1-3-5 as extended.

Extended Harmony Chords Series 1
https://www.guitartricks.com/tutorial.php/1166/

"does the term differ... depending on if it's just octaves of the 1, m3/3, 5... or other scale degrees added or substituted?

Chords with other scale degrees are labelled by those degrees as well as with various chord quality terms:  add 9 , sus 4, etc.

Hope that helps!

"hope that helps"

sort of.

I'm wanting to know if there's a term for a {"chord" that is just a triad with octaves of the of 1, 3, 5}

I already know about terms like "add9" etc; and what they designate.
(Although I wasn't clear that said "qualities" are covered by the larger term of "extension")

I'm asking about a general term/label (such as "scale" "chord" "arpeggio") to apply to this; 
for the purposes of my [internal processing] of information and concepts.

It sounds like you are saying a {chord "extension"} = {additional scale degrees; beyond the pure triad}...

So would "expanded" be a good term for a

{"chord" that is just a triad with octaves of the of 1, 3, 5}?

or is there some other that exists; or you suggest?

It seems like "chords" refers to any triad with additional octaves of the 1,3,5

and then triad refers to just the pure 1,3,5

which is kinda stupid to me:

it makes "triads" way more mysterious than they actually are.

triads are just "chords" to me.

and so I want a term that refers to a triad/chord that is just octaves of the core 1,3,5.

I'll try again!

"I'm wanting to know if there's a term for a {"chord" that is just a triad with octaves of the of 1, 3, 5}"

No.  It's just a chord.

"It sounds like you are saying a {chord "extension"} = {additional scale degrees; beyond the pure triad}..."

In general, yes.  But I'm referring to scale degrees other than 1-3-5 in this case.  There are differences in what some people consider "official" extensions.  Mostly whether or not to include the 7th.  There are other terms for various sets:  added, suspended, slash, poly.  But again, all of those are for chords containing scale degrees other than 1-3-5.

"So would "expanded" be a good term for a {"chord" that is just a triad with octaves of the of 1, 3, 5}?"

If it helps your conceptual process, yes.

I think for most people going that far into music theory identification & conceptualizing the default is to to refer to notation because it is the most precise way to identify & communicate the info.  There isn't a generic term for it because that's what voicings & notation indicate.

"It seems like "chords" refers to any triad with additional octaves of the 1,3,5"

Yes.

"and then triad refers to just the pure 1,3,5"

Yes.

"which is kinda stupid to me: it makes "triads" way more mysterious than they actually are."

Ha!  I can see how you could come to that conclusion.  :)  Triads are indeed just a very precise & smaller set of the larger term chords.  Chords is an extremely large set that contains a wide variety of possible notes.

"triads are just "chords" to me."

Although you can play triads (& they are found in many musical contexts), the term is often used as a conceptual unit for the bare minimum elements (smallest necessary set) for any given chord.

"and so I want a term that refers to a triad/chord that is just octaves of the core 1,3,5."

The best I can offer you is to get precise about the qualities of said chord: major, minor, diminished, augmented, dominant, etc.

But your term expanded seems like a good choice for your own purposes.

Maybe that helped more?!

"Maybe that helped more?!"

It did indeed

(thank you)

Good deal!