The flamenco is a lively, hot blooded music that originated from Spain. One tuning that can produce the fiery flamenco sound relies on the bright sound of a D major chord. With the strings tuned to this chord, the somewhat dissonant interval between the third and fourth strings becomes a pleasing major third, while the bottom three strings can be barred into a root fifth chord.
Strum the sixth string. The sounding pitch for a properly tuned flamenco guitar is D, one whole step below the normal sounding pitch of E. On a piano, this D is found five full steps below middle C.
Check the tuning of the fifth string. If you began in standard tuning, the pitch of this string remains unchanged in flamenco tuning: the A immediately below middle C.
Check the tuning of the fourth string. If you started in standard tuning, the pitch of this string remains the same, a D exactly one step above middle C.
Drop the pitch of the third string by a half step from G to F#. If your flamenco guitar is not in standard tuning, you can find this note an augmented fourth above middle C, or three whole steps above middle C.
Adjust the sounding pitch of the second string to B. On the piano, this note is found a major seventh above middle C. This note also happens to be the standard tuning for the second string.
Tune the highest string of the flamenco guitar to E. If you are using a piano as a tuning source, this note is found an octave and a major third above middle C. High E is the standard pitch for the first string.
Double check the tuning. As you tune a flamenco guitar, some of the other strings may slip slightly out of tune in response the the changing string tension on the bridge. You might have to tweak your tuning a couple of times before the guitar remains in tune.
Flamenco tuning bears a close resemblance to another popular alternate tuning, the drop D tuning. Flamenco guitar tuning differs from this tuning only in the sounding pitch of the third string, which is a half step lower than normal. If you are stuck in a musical rut, try playing a drop D song, such as Soundgarden's "Outshined," with the flamenco tuning. The first, second third and fourth strings have a very interesting relationship in flamenco tuning. When barred, they form a major sixth chord with a suspended ninth, spelled D F# B E in D major. If the third string is omitted, the remaining notes are musically ambiguous meaning they do not clearly belong to the minor or major scale. Something fun to play with.
Alternate tunings for the guitar are addictive. Once you start fiddling with the different ways a guitar can be tuned, you will never play in standard tuning again.