Hi gillymor,
In answer to your question, both.
Once you start fretting from the 4th fret up there’s a noticeable sharpness to the note on a guitar, particularly with the lower E and A strings. This is aggravated if you pick hard on the string, causing the more to pitch further sharp.
It’s the same with a capo.
I’ve noticed it on all guitars but it’s all the more pronounced when playing with other, less affected instruments.
Given it’s just “one of those things” to be tolerated, I was very pleasantly surprised to see that some serious musicians have taken steps to minimise and compensate for this shortcoming.
I have a very expensive floor tuner which shows all six strings in led display but which doesn’t offer adjustment by the “cent”, so I’m hoping this clip on, with its “sweetened” feature offers an improvement.
I’m hoping to hear from others who have used these adjusted tunings
C-flat