Sometimes you need to tune your guitar to another instrument, or you'll need to tune it when you don't have an electronic tuner handy. This video shows you how to do that. Start with the A string, and make sure that's in tune with the other instrument. Put your finger on the fifth fret of the low E string and play the E and A strings together. If they sound the same, they're are in tune with each other. If not, adjust the E string to make it match the A. Next, tune the D string by fretting the A string at the fifth fret, and adjusting the D string so that the pitches match. Repeat the process to tune the G string, matching it to the D fretted on the 5th fret. To tune the B string, fret the G string at the fourth fret rather than the fifth and adjust so that the B string matches the G. To tune the high E, fret the B string on the fifth fret and adjust the E string to match. If you follow these instructions, you won't need an electronic tuner to tune your guitar.