If you've ever hammered a guitar string, then you've sniffed the beginnings of a new, cult guitar style. In case you hadn't noticed, there's presently a erase for pounding the strings against the fretboard, not with plectrums, but with the fingers of both hands.

Eddie Van Halen has his jaguar paced runs at one end of the scale, while jazz exponent Stanley Jordan is exploring an unbelievable piano-like technique of whole chords, bass lines and melodies at the far edge.

Somewhere in between, for us mere humanoids, there's room to examine what is practically possible from single string hammers. Writer and guitarist Paul Madden has begun by breaking down one chord into its component notes and studying the single string potential, in preparation for a book on the subject to be published later this year. Let One Two show you the first few tricks...

First, an explanation. What is a single string chord? If we take the chord of E major as an example, we know that the chord is formed by playing three notes from the scale of E major — the root note E, the third note Ab, and the fifth note B.

If we play the chord of E major at the first position (figure 1), we can examine how the chord is constructed. The sixth string sounds low E — the root note of the chord; the fifth string sounds B — the fifth note; the fourth string sounds E again; the third string sounds Ab — the third note; the second string sounds the fifth note again, and the first string sounds the root, E again.

This kind of examination can be applied to absolutely every chord known to mankind. The main principle is that the chord is played across the strings, covering a wide range of the notes available on the guitar.

Now the difference between the accepted chord shape and the single-string chord shape should become obvious. The root note, the third note and the fifth note of the chord are played on one string only.

If we apply the chord of E major to the first string we find the root note E at the twelfth fret and, of course, the open string, the third note Ab , at the fourth and sixteenth frets, and the fifth note B at the seventh and nineteenth frets (figure 2). By playing these notes in rapid succession we should be able to simulate the chord of E major.

Derek Jewell, in his Sunday Times column recently, described the action of playing single-string chords as 'scarcely credible' and compared it to that of playing piano. In fact the actions required of the left hand (I assume that the reader is right handed) are more comparable to the action of a harpsichord. The fingers of the left hand must not only fret the notes, they must also pluck the strings.

Let's try playing E major, firstly with only the left hand (figures 3, 4 and 5), and then with the left and right hands (figures 7, 8, 9). Ultimately, all chords will be played with both hands, as you need more than two fingers to play E11 and E13.

E major with the left hand only

We will use the first and fourth fingers of the left hand (see figure 6). Place the first finger on the first string at the fourth fret. (Keep your right hand behind your back!) Now hammer down with your fourth finger onto the string at the seventh fret. You will hear the note B sound quite clearly.

Now this is where you must pluck the string as you pull-off the fourth finger. Keep the finger on the string as you pull it down away from you — the string will just release itself from your grip and in doing so, will actually sound the Ab at the fourth fret.

Compare this plucking action to that of just lifting the fourth finger away from the string. You get a much louder and attacking sound by plucking. You can, of course, revert to the lifting action to obtain a quieter effect.

Finally, pluck-off the first finger to sound the open E (see figure 4) and hammer back onto the seventh fret with the fourth finger to sound B and repeat the whole process. This action is an integral part of the technique and must be practised until all the notes can be sounded cleanly without buzzes and rattles. The faster you play this sequence, the more the ear is fooled into hearing an E major!

The notes can be played in any sequence — try B, E, then Ab. Or try repeating Ab like this — B, A b, E, Ab, repeat.

E Major with both hands

If you hold a pick between your thumb and first finger, the finger to use for this exercise is your second finger; or put the pick between your lips and use the first finger if you find this awkward. Some guitarists take the logical path of holding the pick between the thumb and second finger, thus leaving the first finger free to hammer down on the fingerboard. (This also allows you to pick out harmonics anywhere on the fingerboard.)

Stop the first string at the fourth fret, then hammer down at the twelfth fret with the second finger of the right hand. You will hear the high E sound. Now flick the finger downwards, try to take the string with you slightly, but don't force it off the fingerboard as the result will be an offensive click. The action should imitate the plucking that the fourth finger of the left hand was doing earlier. The result will be the sounding of the Ab that you are stopping at the fourth fret.

Hammer-on with the fourth finger of the left hand at the seventh fret to sound the B. Finally, hammer down at the twelfth fret with the right-hand finger to sound the E again. Repeat the actions to simulate the chord of E major.

Incorporating the open string

Obviously the open string can be incorporated only if that note (low E, A, D, G, B or high E) forms part of the chord that you want to play. In the case of E major that requirement is fulfilled.

Again, the sequence is up to you, for our example 1 have chosen high E, B, Ab, low E, repeat.

Stop the first string at the seventh fret with the fourth finger. Make sure that your first finger is in position at the fourth fret, ready. Hammer down with the right-hand finger at the twelfth fret to sound the high E. Pluck-off to sound the B, pluck-off the fourth finger to sound the Ab , then pluck-off the first finger to sound the low E. Remember, take your time if this seems difficult, if your actions are correct then the speed will just follow.

Paul Madden plays lead guitar for THE HURT. 'SINGLE STRING CHORDS — THE COMPLETE GUIDE' will be published by Keen & Keen in August.