The modern harp is sort of mysterious as far as how it works, isn't it? And some people (a lot of people) just don't know much about the harp, anyway. So I've decided to put together a fun little tutorial! I hope it's fun--and simple. Tell me if something is still confusing.
This is a Salvi concert grand pedal harp; Diana model in mahogany finish.
Part 1 - Mechanics & Pedals
Surprise! The harp has 7 pedals (they do not function like a piano's 3 pedals). There's one pedal for each note in a scale (not each string).
The chains move these discs, which pinch the strings. In this picture, the discs are in the "open" position, leaving the notes "flat" (lower pitch).
This shows the upper disc pinching the red string (C) so that it is now raised in pitch to C natural.
The science of how that works is that a shorter string produces a higher sound. When the discs "pinch" the string, the string is essentially shortened a half-step (just enough to bring the pitch up half an interval).
I use pedal charts like this on my music. If I leave the pedals up (like in the first picture of the pedals), the notes are flat. That top symbol, "b," represents "flat." The middle symbol is "natural," and the third symbol (#) is "sharp."
Take a look inside a harp factory!