I think the reason they changed it was to try and make it easier for controller users. And to be honest, it IS easier for controller users now. But it just completely screws over people who got used to playing on a keyboard.

Another reason why they changed it is because you required a lot of keys in a lot of hotbars to play your songs. Dedicated players (like me) changed their entire keybinds just so they could play songs on their Bards. I couldn't even move my character with WASD anymore, but that's fine since I play the game with a controller nowadays.

Admitedly, this new system frees up our hotbars and allows us to play faster, so it's not all that bad. However, the new harp sounds DO sound awful compared to before the patch, and having to manually change octaves is just unrealistic if you plan on playing advanced songs. They really need to allow us to set individual keys for each octave...