How to be accurate in your harp tuning
Most people would think that the best way to tune a harp is by ear — by listening carefully as you change the tension on the strings. I have a friend who plays Celtic harps and she relies on an electric tuner — she says that it is more accurate, because it allows her, via the LCD display, to know exactly when her strings have been tuned to the proper range. In this way she does not need to depend upon the sensitivity of her own ears — her harp is tuned consistently to the proper pitch, every time she uses it.