In Remnant 2, there are a lot of intriguing puzzles in with Yaesha and The water harp puzzle is one of them. It’s vital to keep in mind that the problem won’t solve until you’ve advanced the main story sufficiently. Check out the following instructions on how to complete the water harp puzzle.

The actual water harp is made up of a sizable spool connected to a massive mechanical harp. You’ll activate the harp with a water wheel once you’ve reached the appropriate point in the Ravager plot. After that, you can proceed to the device to set up a number of pins so that the correct sounds are played.
There is a book nearby that has the answer to the water harp. It’s on a nearby desk and its first page reads as follows:

You must insert a pin under the appropriate symbols on the first page’s musical notation in order to play a particular song. Check out the symbols on the harp by going there. Next, choose a row-by-row pin to lift. The arrangement of the pins on the water harp should be 5, 0, 4, 3, 4, 1, given the placement of these symbols on the harp. Pull the lever next to the harp to start it after you’ve entered that pattern.
Alternatively, Begin by removing the peg positioned at the fifth spot on the top row. Move down to the third row and extract the fourth peg. Proceed to the fifth row, where you should pull out the third peg, followed by the fourth peg on the sixth row. Continuing on, take out the first peg from the seventh row. As you advance, skip the second and fourth rows, then the eighth row. This sequence of actions will guide you through the pegs, adhering to the specified instructions.
You can also perform a different tune on the harp to unlock the Bolt Driver Handgun. The right way to release those pins is in this order: 1, 4, 0, 2, 5, 0, 3, 0.