When the guqin uses the traditional winding method, the stringer often finds that the pitch changes very quickly after they are well wound, and it will soon drop; when the player uses the traditional winding method to play , sometimes you will find that the strings will slacken and run out of tone in the middle, and the pitch will drop.

In both cases, "virtual tension" is at play.

The traditional winding method of the guqin is to fix the strings at the left and right ends by the goose feet and the qin qin respectively. Pressure is used to hold the strings in place, and the right side is pulled tight by a velvet buckle around the truss.

The goose foot on the left cannot be adjusted, while the fixed end on the right can adjust the length of the velvet button by rotating the shaft, thereby indirectly controlling the tension and pitch of the strings.

This creates a problem that if the strings wrapped around the goose's feet are not sufficiently taut, or the velvet buttons attached to the strings are not taut enough, the tension of the strings will not stabilize.

For example, when the strings on the wild goose feet are not tightly wound, they are pulled by their own tension, so that the strings wound on the wild goose feet are continuously tightened, but the tension of the strings is decreasing, which will cause the pitch instability;

If the velvet buckle is only loosened when the violin shaft is rotated to adjust the pitch, or the rope end is pushed with the left hand when the velvet buckle is tightened, the velvet buckle is not in the state of maximum tension. The fingering of the strum will cause the velvet button to tighten and loosen the string.

After the string is stretched, it is in a relatively stable state. This kind of tension that exists before the tension is stabilized and is eliminated after it is stabilized is called "virtual tension".

Changes in string tension can cause pitch changes, which have a huge impact on both stringing and strumming. The impact on the playing is that if it is light, it will make people feel that the pitch is out of tune.

The solution to "virtual tension" is to remove it before you try to play it.

When the experienced qin players are winding the strings, they often pull the pitch of the strings slightly higher than the required pitch, and then let them rest for a period of time, or use artificial pulling to gradually tighten the strings on the goose feet. Makes the string release "virtual tension".

When rotating the truss to adjust the pitch (especially after loosening the strings), use your fingers to pinch the midpoint of the string and pull it upwards to make the strings wrapped around the goose feet tighter, and to adjust the tension of the velvet buckle bigger.

After this adjustment, the tension of the strings is basically stable, and there will be no major changes. Correspondingly, the examination of intonation during tuning should also take the strings after releasing the "virtual tension" as the object.

A string that has released "virtual tension" has relatively stable tension, and will maintain a relatively stable pitch from the beginning to the end of the playing.