Shed sea of Orryx
The moon Orryx cracked on a windless night and shed its inner sea as salt. The salt remembered every song it had ever been, and where it settled the ground became glass that can hold a chord.
Choir-Keepers planted resonator spires to turn weather into harmony. When a Keeper was finished, their lantern stayed behind and kept walking. Those are the motes. Haloferns grow in the rings a song leaves on the salt. The arches are places someone stopped to listen, and the salt rose around them.
You were never written into a spire. The plain does not know your name, so it cannot keep your feet. There is no rim. There are only measures. Walk, and let distance change the chord.