A barre performs the same function as a cejilla, only it can move, and is made only with your left index finger. It provides a basis for chords and melodies in higher fret positions than we have used to date. It also allows the other fingers to use similar chord shapes to ones we have already learned, with one difference: the chords are in a higher pitch, since the previously played chords were on open strings; these are stopped by the finger’s action on the strings. Make a barre by placing your left index finger straight across all six strings. This will stop them simultaneously behind the same fret.
When you see the letter ‘C’ above a chord, written with a Roman numeral following it, it indicates that you are to make an index finger barre across all six strings. The ‘C’ stands for ‘cejilla,’ and is followed by a Roman numeral which indicates the number of the fret behind which you place your index finger. In some cases, you will not need to stop all six strings. If you see the notation ½ C, it means that you will stop only the top four strings. This notation is rather confusing, since four strings out of six does not equal one-half. A better notation, which we will use here, indicates the precise number of strings you need to stop expressed as a fraction in sixths, not reduced to its lowest common denominator. For example, the notation ‘4/6 C’ means that the barre will stop only the four top strings; while ‘3/6 C’ would indicate that you should stop the top three.
Do not be discouraged from trying to master the Flamenco guitar because improper technique on the barre causes you to expend too much effort, resulting in tense fingers, which in turn can cause a spasm in your fingers. Use this technique instead, and reduce the tension in your fingers. Very little pressure is required to stop all six strings firmly, producing clear notes. Begin by straightening your index finger, laying it across the strings right behind the first fret as lightly as you can. To make it easier, keep your left hand in a comfortable yet efficient position, relaxing your wrist and holding it forward at an angle with your forearm. Flex your other fingers into their positions on the strings behind the correct frets. Next, put sufficient pressure between your thumb and fingers to bring all six strings firmly against the frets, stopping them securely. Play all six strings with a slow, downward sweep by your right thumb so that you can get a good note from each string from the sixth to the first. For this to be easily done, the left hand must be in a good position, with the wrist relaxed. If at first you cannot sound clean notes on the strings, move the same chord shape up to a fret position which lies higher up on the guitar, where the frets lie closer to each other.