And sparkling evermore, (28)
At a certain point, before everything falls apart, we almost get into My Little Pony territory here. Everything is so happy and sparkly and gem-encrusted and shiny that it almost makes our teeth hurt. It's almost as if the poem's description gets wound up to the point where something has to give. And it definitely does…
In voices of surpassing beauty,The wit and wisdom of their king. (31-32)
The spirits of the palace are so happy that they sing constantly (and sound great, of course—no off-key singing here). They sing to celebrate how wise and smart their king is. If we follow the epic metaphor in this poem, that the palace is like a human head, then at this point all is well with the symbolic head. The mind is still sane and happy, so the speech that comes from the head is evidence of that wise and cheerful mind.