The explanation of fixed form nouns in the history of Western music is as follows:

The earliest form of Western polyphonic music was Organon.

Oganon. Organon, also known as flower-singing Organon, is the earliest form of polyphonic music in Europe. It is formed by adding a parallel fourth or fifth voice part below the Gregorian chant one note for one. Music is an art form and cultural activity whose medium is sound organized in time.

In the 9th century AD, monk musicians engaged in religious activities began to add a parallel fourth or fifth tune below the single line melody of Gregorian chant. Therefore, the added melody and the original melody form a simple "polyphonic" form. This form of "polyphony" is the "Olganon".

Later, the prosperity of secular music promoted the development of religious music, and the "polyphonic" form of Organon also changed. This is adding octaves, fourths, and fifths above the psalm melody. By the 12th and 13th centuries, with the development of composers from Notre Dame de Paris, "Olganon" had new developments.

This enhances the independence of each voice. Due to the increased independence of the voices, the melody of the original Gregorian chant is no longer the main line of the music. As the melody becomes more complex, the counterpoint between the parts becomes increasingly strict. Thus, polyphonic music was officially born. The emergence and development of "Olganon" greatly promoted the development of Western polyphonic music.

History of the development of Organon

1. Parallel Organon: At the bottom of the chant melody, a part that is completely parallel to it is attached, usually four or five degrees apart. mode parallel, this voice is called an Organon voice, and this form is also called a Parallel Organon.

2. Parallel Organon variant: Parallel Organon variant has appeared since the 11th century. It is also based on the melody of the psalm. The difference is that the additional parts are based on the psalm. The chant starts from the unison, then moves obliquely, starts parallel movement after reaching the fourth degree, and finally merges into the unison through the oblique movement.

3. Free or reverse Organon: Popular around the 11th century, this form of Organon uses the original chant as the melody, placed in the low part, with the upper part In addition to forming a parallel or diagonal progression with the low voice, the additional voice often also forms a reverse progression of tone to tone.