1.
Go to a website that offers a mood tool.
2.
Click on the string pitch that you know is out
3.
Pick up the string that is inaccessible.
4.
Tighten the string by turning the tuning knob (usually clockwise to tighten) if it sounds lower than the correct tone you heard from the online source.
5.
Loosen the string by turning the tuning knob (usually counterclockwise to release) if it sounds higher than the correct pitch from the online receiver.
6.
Continue making gradual adjustments with the setting key until the string sounds exactly like the online tuner.
7.
Check the other strings with the online tuner. Sometimes other strings can be inaccessible, and you may not be aware of it. This is also useful if you are not sure which string is missing.
No matter what song you play or how well you play, you will not win a pleasant sound if you have one or more guitar strings that are no longer in place. Sometimes it can be difficult to tell which strings are missing. Other times, you may be able to isolate the string that needs to be tuned, but you still need a reference point for how much you want to raise or lower the tone. If you have Internet access, you do not even need to bother with a pitch pipe, keyboard or electronic tuner to tune your guitar. You can follow a few simple steps and use an online tuner to help you restore the string to the correct pitch.
Source:danspela.com