Drop B tuning gives a low, heavy sound that is used extensively by some metal and grunge bands. Like Drop D tuning, Drop B lets you play power chords by barring a single finger across the bottom three strings. The difference is that while drop D is only slightly heavier sounding than standard tuning, drop B is another three half-steps lower, giving a much darker and heavier sound.
Get heavy strings. Use a set of 0.013 to 0.056 gauge strings or heavier. Drop B tuning is lower, which means there is less tension in the strings. Lighter guitar strings won't have enough tension in this tuning, which will cause them to rattle and sound bad.
Tune the low string to B. This is B1, or 61.74 Hz.
Tune the second string to F#2, at 92.50 Hz. If you are using relative tuning, press the low string at the 7th fret to get the tone for the 2nd string.
Tune the third string to B2 at 123.47 Hz. Press down the second string at the 5th fret to get the right tone for relative tuning.
Tune the fourth string to E3 at 164.81 Hz. Press the third string at the 5th fret to get the correct pitch.
Tune the fifth string to G#3 at 207.65 Hz. Press down the fourth string at the 4th fret for the note.
Tune the sixth string to C#4 at 277.18 Hz. Press the 5th fret of the fifth string to get the correct pitch if you are using relative tuning.
Drop B tuning requires you to use different chords than you would for standard tuning. If you don't want to have to learn a whole new tuning, simply use B tuning instead of drop B. Start with standard tuning, then tune everything down five half-steps to give you B, E, A, D, F? and B. You will still be able to use the same chords, but they will be transposed down.