Curiosity: Why Exactly "∆"

Great question. I searched a bit on the internet but it seems there is no certain answer. Some attribute it to Jamey Aebersold, others date it back to the '50s, but no one seems to know the reason. You find an infinity of answers ranging from ancient Egypt (...) to the fact that originally it was followed by 7 and represented only an upward arrow indicating the major seventh. Maybe it's just a graphic necessity, since the circle had already been used and a square is not so fast to write...

Just imagine that when I'm in a hurry I use the Greek "Pi" to represent pentatonics, rather than constantly writing out the full term... if someone were to adopt it by chance, they would rack their brains trying to understand its origin... ;-)

P.S. it also remains a mystery why the ∆ is obtained by typing alt+H ...

A guy once gave me an almost reasonable explanation, since ∆ is the fourth letter of the Greek alphabet, the logic lies in the superposition of fourth intervals, which added together make a major seventh interval.

C-F + F-B=C-B indeed ∆

Now, is ∆ or M better?

Regardless of the reasons, in the logic of detaching from the mode and the reference scale, thereby increasing practicality during improvisation, I find ∆ more adequate.

But there would be other dysfunctions

I had also read this interpretation. Generally, I distinguish between analytical symbols (Cm7b5) and synthetic ones (CØ); the former describe the chord in detail, while the latter can allow for greater reading speed. In the USA, the correctness of using one system or the other is debated; personally, I prefer the latter.

Ok, I'll stop asking myself too many questions

DrJellyfish wrote:

P.S. it also remains a mystery why the ∆ is obtained by typing alt+H ...

...no...explain the alt+H story to me better?

To write ∆, I went through all sorts of trouble ... ha ha ha