To play certain songs on your guitar, including many hard rock songs, you may need to tune your guitar to drop D tuning. Drop D is when the lowest sixth string has been tuned town a whole step. Experience players may be able to tune to drop D by ear, but it can also be easily accomplished used an electronic tuner. Once you’ve tuned to drop D you can the tune all of your strings down a half step so that your guitar is tuned in drop D flat.
Tune your guitar normally using a tuner for accuracy. The standard E tuning will be in be in E, A, D, G, B and E.
Place your index finger on the second string of the fifth fret. Play this note, which is the D note.
Use your tuner and drop your low E string to a D note. Strum the low E string until it reaches the D note on the tuner and then move your index finger back to the second string of the fifth fret again.
Play the lower E string while holding down the D note at the same time. Continue to tune down the E string one step, if necessary, until the notes match up. The guitar is now turned to drop D.
Go back up to the last string, which should be still tuned to an E. Start tuning down every string a half step, including the lowest string again. Your guitar will now be tuned to drop D flat.