evilpunk

For drop D tuning (DADGBE) bet the 7th fret of the 6th string to sound the same as the 5th string played open.

Alternatively, if you are trying to develope an "ear" get the 12th fret of the 6th string to harmonise with the 4th string played open. If they sound exactly the same ie. same pitch you have gone an octave too high. You are aiming for 1 octave lower than the 4th string

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