Guitar Tuner

Another method is to use a guitar tuner. There are various versions of these. The picture below shows a standard guitar tuner. These work by plugging your guitar lead into the input. The needle on the screen moves from left to right when the string is plucked. If the needle is to the left the string is too low (flat) and needs to be raised in pitch. If the needle is to the right the string is too high (sharp). Once the needle is in the middle the string is in tune