 For example; in a simple case of an ascending semitone slur (Hammer-on), a note stopped by the first finger of the left hand at the fifth fret is first played in normal manner, then, without the right hand doing anything further, the second finger of the left-hand is placed straight down at the sixth fret on the same string, using its momentum to raise the tone of the still-ringing string by a semitone.A descending slur (Pull-off) is simply the opposite of the above, the slur begins on the higher note and it is common that the finger pressing the higher note actively plucks the string as it lifts, causing the string to vibrate from the fret that the lower finger is depressing.The lower finger is usually in position and pressing before the procedure begins.