system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:Why do harps have that curve at the top?

Doesn't that create discrepancies in the lengths of the strings? Wouldn't it make the harp harder to play because pitches are switched around?
gpt
If you used the same type of string for every note, then there would have to be a geometric curve as the length would need to double every twelve notes. Over a few octaves this would be unworkable because you'd end up with a 12 foot high harp.

Luckily, there's more ways to change the pitch of a string than to change its length. You can also change the thickness of it. However, thicker strings don't produce as nice a sound as thinner ones, so you have to strike a balance.

That balance is struck by having a curve. You can choose the curve with various criteria including making it pretty, making it sound a certain way, and also lining up a particular fraction of the length of the strings which is the optimum plucking point.