Techniques executed by both hands together are more difficult to achieve, for example, "qia cuo san sheng" 〈掐撮三聲〉 (a combination of hammering on and off then plucking two strings, then repeating), to more exciting forms, like pressing of all seven strings with the left, then strumming all the strings with the right, then the left hand quickly moves up the qin, creating a rolling sound like a bucket of water being thrown in a deep pool of water (this technique is used in the Shu style of "Liu Shui" to copy the sound of water).