One of the initial sections of musical notation and solfeggio is the study of intervals. There are seven of them. At the moment, we are interested in the interval, called in the music "octave". Its name comes from the Latin word "octo", which means "eight." Consider the basic concepts associated with this interval.
Octave: what is it?
In principle, the very meaning of the concept of an octave has several basic interpretations. This term is called the eighth stage of the scale, the interval, the range of the natural scale and the registers of notes (sounds) on a musical instrument.
Consider the octave interval. What is it from the point of view of solfeggio? These are two sounds together, differing in sound pitch by half. If we give an example using the piano keyboard, these are, say, two identical note positions, one of which is located above the register.
As an interval, an octave has three types: pure, enlarged, and reduced. As a rule, music uses mostly pure octave. It is designated as "p8".
The composition of the octave and scale
How else is the concept of “octave” interpreted? What is it in a natural scale, it is easy to understand if you look at the main notes and intervals that are included in it. As already clear, there are only eight notes in it, with the first and last notes coinciding in name, but differ in pitch. The octave notes for the simplest basic scale in C major represent the following sequence: C, D, E, F, G, A, H, C, D, E, F, G, A, H, in C major, C, D, E, F, G, A, H C.
Each sound in an octave (if we consider it from the point of view of the sound range) is separated from the neighboring one interval, called a semitone. Two halftones form a tone. As is already easy to see, the entire octave consists entirely of twelve semitones (this is clearly visible on the piano, where there are white and black keys).
Now a few more words about the octave interval. What is this in understanding the interval for each particular gamut? Everything is very simple. This is an alternation of notes and the intervals formed between them, taking into account key signs and rules for constructing the main types of scales (major and minor).
Any major scale is an alternation of intervals in strict sequence, regardless of the signs in the key: tone, tone, semitone, tone, tone, tone, semitone.
There are rules for minor scales. For a natural minor, such a sequence is constructed as follows: tone, half tone, tone, tone, half tone, tone, tone. These are basic sequences, so to speak, since now varieties of scales such as harmonic or melodic are not taken into account, not to mention various frets or exotic oriental scales in which a quarter tone is taken as the basis for the construction.
Octave voices and musical instruments
Now consider another application of what we call the “octave” in music. What is this when applied to a musical instrument, you can understand if you look, for example, on the piano. In fact, these are the same registers, spaced from each other at an equal distance up or down.
From a musical point of view, the classification of octaves is adopted precisely by the piano keyboard. The main ones are: subcontroctava, controctava, small octave, large octave and then from the first to the fifth (a total of nine). The first and last octaves are incomplete, since sounds below and above the specified range are hardly perceived by the human ear.
And also about the concept of "octave." What does this apply to the human voice? It is clear, probably, that this is a certain range of sounds of different heights that a person can reproduce (sing).
How many octaves a person’s voice supports depends only on the individual structural features of the larynx and ligaments. According to statistics, in an ordinary person this range is one and a half to two octaves.
Naturally, if you engage in the development of vocal data, you can achieve a significant expansion of their capabilities. Today you can meet a lot of professional vocalists in whom such a range can reach four to five octaves. No need to go far. Take at least such a famous artist as King Diamond. His voice range is four and a half octaves.
It is not surprising that in his gloomy creations he easily jumps from low to high sound and even performs the parts of all the characters of his mini-operas (no matter who owns this part, a man, woman, old woman, child or a ghost in the form of a monster) . Most interestingly, the recording does not use special corrective devices similar to those that were used to sound the singer in the movie "The Fifth Element". There the vocal is only half natural, the rest is synthesized sound.
Using an octave in music
Musically, the octave as an interval is used quite often. Unlike one clear, lonely-sounding note, a second upper or lower sound adds fresh color. It is no coincidence that initially for guitarists, in addition to standard lotions, special devices called octaves were developed.
They have gained immense popularity among many performers. For example, very often they are used by such celebrities as Brian May, Yngwie Malmsteen, Steve Wye and many others.