Nineteen tone equal temperament (nineteen equally spaced notes per octave instead of the usual twelve) is a popular choice for microtonal composers. It has major and minor triads that are closer to just intonation than in twelve tone equal temperament. It is generally regarded as a more consonant tuning than standard twelve tone equal temperament.
Personally, I find Nineteen tone equal temperament to be somewhat unsettling to work with. Its fifth and major third are both flatter than purely tuned intervals and I usually prefer major thirds that are sharper than purely tuned (5/4) and closer to the Pythagorean major third (81/64).
In any case, I wanted to experiment with this temperament. I came up with a piece for two pianos that could actually be played in real life if the two pianos were tuned to share the 19 tones per octave. I know this is an awkward way to perform, but this is actually done successfully on occasion during concerts. I decided to explore this temperament's darker side. Here is my Rondo in minor modes for two pianos in nineteen tone equal temperament.
See also my Nocturne for two pianos in seventeen tone equal temperament.