This is a special effect which could be considered the Left Hand equivalent of the bow’s flying staccato. Here, the left hand does a glissando up or down the string, but rather than sliding smoothly, it does it with machine-gun-like impulses. As with the bow’s flying staccato, this is the perfect opposite of a smooth relaxed movement. It is deliberately and necessarily tense and “jerky” – basically a controlled spasm. This is of course absolutely the opposite type of movement to the smooth, flowing, relaxed movements which we spend so much of our time at the cello trying to achieve!
This movement is normally used for spectacular, fast, chromatic scales on one string in which each impulse corresponds to one semitone as in the following repertoire examples: