Electronic organ is the backbone of electro-acoustic band, which is often used to solo the main melody with rich harmony. It also often appears in the form of solo instruments, which has distinct characteristics of the times. However, the limitations of the electronic organ are also very obvious: melody and harmony lack volume changes and are too harmonious and single; When imitating various orchestral instruments, the technique is slightly monotonous.
The automatic rhythm part of the electronic organ provides favorable conditions for teachers to teach students a sense of rhythm. Teachers can let students beat time repeatedly with automatic rhythm, and even exercise, such as stepping, walking and doing rhythmic exercises, from which they can experience the rhythm of various rhythms with their hearts and bodies. Moreover, you can understand all kinds of music styles and increase your comprehensive music literacy.
A large part of the performance of popular electronic organ is accomplished by automatic chord accompaniment. In music, the connection of chords promotes melody, and different harmony connections form different musical colors. (Note: The synthesizer has no automatic accompaniment function, similar to arpeggio)
Learning electronic piano is more suitable for children over 5 years old. We use the special function of electronic organ to cultivate students' comprehensive musical ability, thus inspiring them to understand and love music from the heart. Once children master this ability, they can exert their infinite creativity and freely express their inner feelings in the language of music. Children will like and love music more. Modern electronic organ generally adopts PCM sampling sound source. The so-called sampling is to record the sound of an instrument, digitally store it in ROM or FLASH, and then play back the sound when pressing the key. There are even some advanced arranger keyboards that can use external sampling (such as the hard disk timbre of Tyros 3). Modern electronic organ cannot "imitate" the timbre of musical instruments. It uses the timbre of a real instrument. Of course, the sense of force in the electronic organ is essential. Modern waveform memory electronic organ also has filters and oscillators, and can also make and edit timbre through envelope control. Even the FM synthesis mechanism of the old electronic organ is simulated by adding hardware circuits or software. Today's electronic organ is not what it used to be. Many 3000~6000 electronic pianos support more functions. For example, Yamaha's PSR-S650 supports complete XG and GS sound sources, has the mega timbre of real musical instrument technology, and 16M can be loaded into sample-readable ROM, as well as sequencer and accompaniment production functions. It is more convenient for live performances and music production.
Sound source parameters include sampling frequency, quantization accuracy, waveform capacity and maximum polyphony. Please refer to the audio source entry for details.
Of course, there are some old electronic keyboards that only use FM to synthesize sound and use oscillators to simulate the sound of musical instruments, but they have already withdrawn from the market. His working principle is as follows:
The function of an oscillator is to generate an oscillation signal with a certain frequency as required. The oscillating signal is decomposed into signals with different frequencies by the frequency divider and sent to the amplifier, which amplifies the signal and drives the speaker to make sound. The keyboard is actually some switches. If there is no keyboard, signals of many frequencies will enter the power amplifier at the same time, and the sound emitted through the speaker will be messy, not music. Pressing a key of the keyboard is equivalent to turning on a switch, allowing only signals of a certain frequency to enter the amplifier, and the speaker will make a sound. In this way, you can press the keys according to certain playing rules and play wonderful music. The task of power supply is to supply power to all parts.
The working principles of oscillator and frequency divider are further introduced below. Generally, the oscillator adopts LC inductance three-point oscillation circuit. If the influence of transistor, resistor and other factors is ignored, its oscillation frequency f can be determined by the following formula:
As long as the values of inductance L and capacitance C are properly selected, the required signal frequency can be obtained. The frequency divider is a bistable circuit, that is, the transistor BG 1 is on, BG2 is off, BG 1 is off, and BG2 is on. If a signal pulse is input at its input, it will flip once, that is, it will quickly change from one steady state to another. If another signal pulse is input, it will turn over again and return to the initial stable state. Thus, when two signal pulses are input at its input terminal, one signal pulse is obtained at its output terminal. That is to say, the frequency of the output signal is half lower than that of the input signal, just like being divided by 2, so it is called frequency division by two.
It is necessary to use a frequency division circuit for electronic organ. The frequencies of basic scales in music are arranged according to certain rules. Taking the key C as an example, the frequency (in hertz) relationship between tones in a scale is:
Explain that the frequency of a sound is just twice the frequency that is one octave lower than it. So, just divide the frequency of sound by 2 and you can get the frequency of sound that is eight degrees lower than it. For this reason, it is necessary to use a divide-by-two circuit. In this way, as long as the oscillator generates a standard pitch frequency signal, such as a treble signal of "1", it will generate a midrange frequency of "2" by dividing by two, and then generate a bass frequency of "1" by dividing by two. If seven oscillators are made according to the frequency of the highest tone group on the keyboard, a group of low octave scale signals can be obtained by dividing the seven scale signals by two; Divided by two, you can get a set of low octave scale signals. By analogy, you can finally get all the scale signals on the keyboard.
But in fact, we need to make a 12 oscillator and more frequency dividers, because a keyboard has five black keys.