The first record label they were on was Tetragrammaton, not "Tetragrammation".

ICYWW, it's a reference to one of the names of the Abrahamic god, usually transliterated into Greek as YHWH (Tetragrammaton literally means "four letters"), which is where Yahweh/Jehovah is derived from.

(I know this from Foucault's Pendulum.)