Microtonality is the division of an octave into more than the usual twelve tones. I don't know much about this oddity, yet. The pianos in this recording have been retuned so that an octave consists of 17 tones. At first, it just sounded out of tune, but after a few listenings, I realized there is order in the chaos, just not what we normally think of as order. The intervals one thinks of in music do not apply. I suppose intervals heard here could be a major3.35th or a minor 9.17th. However, the re-tuned pianos are normal instruments. The pitches have just been altered.
Youtube is down, I'll link to the weird piece later.
Here is a link to a true microtone piano site. This is so bizzare.
http://www.sauter-pianos.de/english/pia ... otone.html