Prepared pedals

The pedals can be fixed in half position by inserting erasers or other rubber material, for example the rubber tuning key, into the pedal slot. The pedal then stays in the half position. The object is placed above the pedal. The pedal springs inside the pedal mechanism always press the pedals upwards and thus hold the object in place . Therefore, if the pedal is moved the preparation will fall out. 

All the strings that the pedal controls will have a buzzing sound (a pedal buzz sound).

A verbal explanation is required.