Where does “ᾨδεῖον” come from?

ᾨδεῖον (Ancient Greek) comes from Ancient Greek ᾠδή, from Ancient Greek ἀείδω, from Proto-Hellenic awéidō — to sing.

Ancestry of “ᾨδεῖον”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	ᾠδή	song, ode; legend, tale, story
2	Ancient Greek	ἀείδω	To sing, chant, praise; To make various noises:...
3	Proto-Hellenic	awéidō	to sing

ᾨδεῖον — Etymology, Origin & Word History | Etymology Explorer