Has anyone here listened to, performed, studied, or written music which lies outside of the Western 12 evenly spaced notes per octave paradigm? For the purposes of discussion, historical tunings like meantone temperament and Pythagorean tuning can also be considered, though they're usually not considered microtonal.
For those of you who don't know, microtonal music uses "notes between the notes." In the modern Western system, there are 12 notes, each spaced evenly. This is known as 12 tone equal temperament (12 TET) or 12 equal divisions of the octave (12 EDO). This system is used in almost all modern music, even in non-Western countries which didn't historically use it. It works fairly well, but it does have both flaws and limitations.
1. In actuality, there aren't just 12 pitches in an octave. There are infinitely many. Practically speaking, there are still far more than 12 pitches that the human ear can distinguish. This leads to all kinds of new scales and chords.
2. In addition, the 12 EDO system has a flaw in that major thirds are pretty badly out of tune. This is due to a compromise between good fifths and good thirds. The historical quarter-comma meantone temperament goes for perfectly tuned thirds, while Pythagorean tuning goes for perfectly in-tune fifths. The system of 12 EDO is in-between these extremes, but it errs much closer to Pythagorean tuning than quarter-comma meantone.
3. There are also plenty of (reasonable) upper harmonics that aren't addressed at all. The 7th harmonic (for C the 7th harmonic is a Bb that is about a third of a half-step flatter than 12 EDO.) is absent altogether, as are the 11th and 13th harmonics. The 7th harmonic is common in barbershop quartet music, and it also appears in jazz and blues in the form of "blue notes" which require pitch-bending on acoustic instruments. The 11th and 13th harmonics are simply brand new sounds that aren't similar to anything within the common Western cannon, but they are still consonant and in-tune.