I've mentioned this before, and a certain Site Administrator indicated we should probably revisit the topic some time after TH has been released, so I think this is a fair time to re-introduce this idea:
So far, the LPs have each had a distinct tone that could possibly be attributed to an element:
MHTRTC - Air (sounds play out as if at a distance and melodies like dust motes)
Geogaddi - Fire (reduced use of reverb, claustrophobic, dry tones, crackling sounds)
TCH - Water (more polished production/wet or clean sound, juxtaposed with some sounds I would say seem "water-damaged", drums in Dayvan Cowboy sound like a rhythmic representation of waves)
TH - Earth (I had kind of imagined a track like Palace Posey would be on this album even before the release, a sort of tribal/nature tone)
Depending on the mythology used, there could be additional elements in the lineup (Metal, Aether, or if you're a Captain Planet fan, Heart), but in referencing Aquarius it would look like there might have been a restriction to the Zodiac elements. If that is the case, I would anticipate the sound of any new LPs to be far removed from the previous four.