Really small major thirds

Daniel Wolf wrote,

>(e.g. van Zanten's
>study of Cianjuran showed a preference for major thirds around 100 cents)

What's this about?

>To be complete, I should note that there is an informal, non-systematic,
use
>of "mistuned unisons" between instruments in Java. This increases volume

Well, it doesn't increase RMS, but does increase peak volume.