I've received a few emails through my website asking me what a major minor seventh chord was. At first I thought they had mixed up the sequence and were referring to the A-#7 chord (root chord of harmonic minor), and were confused because my site has it as A minor natural 7th (I made custom fonts for the symbols).
But they pointed me to Wikipedia where there seems to be an alternate chord naming system that specifies the triad quality, then the interval quality. Outside of the fact that I think this is very confusing for beginners my questions are this:
What is the actual name of this system (if any)?
What is the purpose/goal of this system?
Is it related to or historically derived from any particular genre of music or school of analysis? Or is just one of those Wikipedia Exclusive type things.
For comparison I learned/teach them like this on my website: Chord and Scale Qualities
Here's the article on Wikipedia: Dominant Seventh Chord Which has been revised since I first saw it.