If Demacia doesn't approve magic

I'd imagine Lestara's got enough influence to be able to sweep a few things under the rug and call in some favours, or maybe Sona's magic stuff's easier to hide considering most of it comes from the etwahl.

Fairly sure no one notices magic coming out of it. TO the average viewer its just an instrument, making beautiful sounds. The old lore suggests that any attack she produces from it are razor sharp gusts of air, that cant be seen. The effect her music produces is magical to the listener as well, but they lack the flashy spell effects we see in game for the sake of clarity.

Thus, to everyone, Sona is just a mute harp player and thats it.

Sona didn't get an updated lore so we don't know. However she likely hides her magical abilities to some extend and the magic in her songs might not be that noticeable(so the people likely believe that she is just so good that her music can encourage you to go beyond your limits)

Is sona's lore up to date? Could be a secret like with lux.

Magic