Okay, I get what you are saying. Two simultaneous notes a minor 2nd apart sound like two distinct notes. But you don't have to narrow the gap by much more befor

Okay, I get what you are saying. Two simultaneous notes a minor 2nd apart sound like two distinct notes. But you don't have to narrow the gap by much more before it sounds like a single note. A very small gap gives a subtle chorus effect, a little wider takes one into honky-tonk piano territory, and wider still perhaps more like a bell, but still sounding like one note. But, as you say this doesn't negate the audibility of microtonal inflections in a melodic line. However, pitch steps smaller that those of 12tet can still provide new chords. For example, in 24tet the triad with a third half-way between minor and major is a distinct and interesting sound. But yes, in 24tet two consecutive pitches sounded together sounds more like a single note with an interesting timbre.