Key refers to the key in music, which refers to the position on the scale corresponding to a single note produced when singing.

For example, CDEFGAB in the scale, from C to D, it goes up one key, and when it goes up one octave, it goes from C4 to C5.

A musical scale is a sequence of tones arranged in whole steps, semitones, and other intervals.

The basic scale is the C major scale. When playing on the piano, all white keys are used. Raising one key refers to the rise in tone from the white key to the next white key, such as C4 to D4. Raising half a key corresponds to the black keys in the piano, which are called semitones, such as C4 to #C4.

Extended information

The change of raising or lowering the tone in the scale is called pitch. The height of the sound is determined by the vibration frequency. The two are positively correlated: the higher the frequency, the higher the frequency. The sound is "high", and vice versa. Low-frequency tones give people a low, thick, and rough feeling; high-frequency tones give people a bright, bright, and sharp feeling.

Each note in the scale can be used as a tonic to establish a mode, which can form 7 different seven-tone natural modes. The natural heptatonic scale is the most widely used seven-tone scale. Its interval organization is that there are 5 whole tones in each octave, divided into two strings and three strings, and the two strings are separated by semitones.

The structural form of tone focuses on referring to the sound sequence based on the specifications of the interval relationship between the sounds within the sound sequence.

The pitch relationship between two musical tones. It can also be expressed in "degree". Taking simple musical notation as an example, from 1 to 1 or from 2 to 2 is a degree, from 1 to 3 or 2 to 4 is a third, and from 1 to 5 is a fifth. Degree is the unit of measurement of the distance between sounds. The distance in pitch between sounds is called an interval.

Baidu Encyclopedia-Musical Scale