Now.
This makes me curious for one particular idea.
Is there a 1:1 correspondence between the fabrial cage metals' effects and the effects of various Rhythms? For example, hypothetically, if the Rhythm of Joy was the "same" as Zinc for a fabrial... Could Singers then modify their Forms with "subforms" by attuning or singing different Rhythms? like the war chants of the Warform listeners on the shattered plains, was that enhancing their Warform's abilities further?