Scales of the World
The Iwato is a Half-Diminished scale type. This Japanese scale is also based off of the Kumoi, but features the famously dissonant flat fifth interval.
In fact we see that the Iwato is much like our Locrian Mode, save that it has no third or sixth.
There are several aspects at play that make the Iwato a powerfully exoic and mysterious scale.
The fact that the flat fifth is used in conjunction with a flat second and a flat seventh, gives the listener an edgey, creeped out feeling much like the diminished scale or Locrian Mode.
This gives the tense sounding tonality an open spacious aspect that makes it even more appealling!
It’s a favorite!