Surprisingly, this manner of speech—with a cadence that imitates the rhythm and music of a song—is natural for spirits. It is the way they talk among themselves, even though they are unaware of doing so. Souls take up the habit of speaking this way right after death. I too was introduced to it, and eventually it became familiar to me. The reason spirits talk this way is that they speak in concert as a community, although they usually do not realize they are doing so. This indicates clearly that all spirits are divided into communities, and that all things are therefore divided into something analogous to communities.
from Secrets of Heaven, Volume 2, Section 1649