Research On The Spectrum Of Piano Sound Under Different Key Touching

Timbre is an essential detail in piano performance. The performance of musical composition can be directly affected by the change of the variety of tone color. Pianists hold that the way of touching key is one absolutely necessary tach in the piano playing. A reasonable way of touching key is a kind of playing technique which has been pursuing by pianists. The main research purpose of this thesis is to analyzing whether different ways of touching key have substantive impact on the musical sound by measure the different dynamics of pressed touch and struck touch. In this thesis, experimental method and statistical analysis methods are adopted, acoustic measurement software is implemented to verify the issues to be researched.This thesis is composed of five chapters. Chapter one gives the classification of the acoustic structure of piano and introduces the composition working principle and its impact on sound of each part of the piano. Also, the structure and work principles of grand piano action system is introduced in detail and the static resistance and dynamic resistance of action system are particularly introduced. In the second chapter, the paper introduces the key of the experiment and the way of touching the key.Chapter two described the selected "pressed touch" and "struck touch" key-touch manners in the experiment and explained the difference between the two key-touch manners. In addition, in-depth analysis of the two key-press manners are given based on literature review. Chapter three introduced the test equipment, preparation work and experimental procedure related to the experiment, the parameters and working principle of the pressure sensor are briefly described as well. In chapter four, introduced the two kinds of key-touch in different dynamics.Whether there is something changed the tension on the key and the string.It is also introduced the duration of the hammer-string. In chapter five, comparative study of frequency spectrum and spectrogram are conducted.Through the study of key-touch intensity, hammer-string intensity and frequency spectrum, spectrogram, finally the article draws conclusion that:1. When playing the piano, finger-key intensity is proportional to the hammer-string intensity, while key-touch intensity and hammer-string intensity have a certain effect on the duration of hammer-string.2. Key pressed are more energy saving than key struck, they also have a certain effect on the duration of hammer-string.3. The energy intensity and number of harmonics^ the duration of homophonic and the number of high order harmonics are obviously affected by the change of intensity of playing.4. Different emergence order of homophonic of "key pressed" and "key struck" can be observed, in general the homophonic of "key pressed" emerged earlier than that of "key struck" 5. At the initial stage of sound, the harmonic energy of "key struck" is generally higher than that of "key pressed"...