Learn how to tune your mandolin using an electronic tuner.
First, let's go over the tuning of the mandolin. Although mandolin players will sometimes use many different tunings when playing, the most popular one and the one primarily used for bluegrass music is standard tuning. From the lowest string set to the highest string set the tuning is GDAE. Memorize this tuning because it will be helpful when you use an electronic tuner. The tuner will listen to the string's pitch and tell you what frequency/note it is currently at. Most of the time the mandolin is close to being in tune, but it just requires some tweaking.
Click the button below to use the online Tunefox mandolin tuner.
The two main terms you'll hear in reference to pitch are 'sharp' and 'flat'. Sharp refers to the note being too high and flat means it's too low. For example, if you play your low E string and the tuner shows that the string is at and F note, you're tuned sharp and need to turn your tuning peg away from your body. For flat, you'll turn your peg towards your body. Watch the video below for a demonstration.