Octave
As octave ( rare: " octave ", from the Latin octava: " the eighth " ) is called in music, an interval that spans a certain divided into 8 pitches of a diatonic, heptatonic scale (eg, C → c). The frequency ratio between low and high tone is exactly 1:2.
Two tones separated by an octave appear very similar, almost like a line ( Prime). It is also said they have the same pitch class. The reason is to be found in the actual tone: sounds of musical instruments are sounds which consist among other things of the fundamental and several overtones. Has the first overtone of the fundamental (usually ) the same frequency as the octave up tone. It is therefore included in the sound of the lower tone. Thus, the octave is the interval after the konsonanteste Prime.
The octave reserves, unlike the other intervals in all temperate moods always the frequency ratio of 2:1 (one exception, however, is the stretch on the piano tuning ). A closing in the octave cadence is called perfect whole circuit.
The octave is in almost all musical cultures of the world is a basic interval, which forms the basic framework for scales usually. Usually these scales extend over a Oktavraum and then repeated in the octave ( such as in the Western tonal system ).
Reed instruments with conical drilled tube (eg oboe, shawm, saxophone) overblow the first time in the octave as well as open flutes (eg flute, recorder ).
Octave is used in the meaning " frequency ratio 2:1 " in physics, acoustics and high frequency technology.
According to recent findings of brain research mammals have a Oktavkartierung in the auditory thalamus.
Subdivision of the tonal space in Oktavräume
The Western tonal system is divided into Oktavräume ( Oktavstreifen ), each extending from the note C to the next higher tone h. For the unambiguous designation of sounds from different Oktavräumen Oktavraum each has its own name and its own notation. So in the short form, the tones of the lower octaves with a capital letter, the higher the lowercase listed (see figure); for any higher or lower octave a bar is also added. Alternatively, the tone letters can valued ( c '= c1) or, even doubled in the lower octaves ( C = C1 = CC). In the spoken form of the note names the name of the octave is prefixed (eg " big d " for D, "is underlined g" g '). The individual Oktavräume, including the usual frequency spaces are as follows:
- Contra - octave, from C ( 32.7 Hz) to H
- Great octave: C ( 65.4 Hz ) to H
- Small octave: c ( 130.8 Hz ) to h
- Remember Underlined octave: from c '( 261.6 Hz ) to h ' ( ing middle a ( a '= 440 Hz) is the normalized pitch )
- Two Coated octave: from c'' ( 523.2 Hz ) to h ''
- Three Coated octave: from c'' ' ( 1047 Hz ) to h '''
- Four Deleted octave: from c '''' ( 2093 Hz ) to h ''''
- Five Deleted octave: from c '''' ' ( 4186 Hz ) to h '''''
- Etc. (in theory there is no upper limit, in fact even the threshold of hearing of infants is exceeded but the latest in the eight -line octave )
In musical notation, a special labeling of notes in very high or very low altitudes is used (see also transposing musical instrument ) to avoid guides. To view the clips with the names 8vb (Italian ottava bassa: " lower octave " ) and 8va (Italian ottava alta, " high octave " ), a shift of one octave up or down to. Rarely encountered are shifts of two octaves ( 15ma and 15mb, Italian quindicesima alta / bassa ), see octave.
Alternative designation systems
In addition to the presented above, in classical music theory widely used system, there are other Tonnamensysteme for unique naming of sounds.
For example, a shorthand notation has been developed which, starting from the 88-key standard keyboard, by one octave from top to bottom, starting each at C. The low C ( C ) is the first C on the keyboard and called C1. The five painted c ( c '''' ') is called, therefore, C8. The tone H is called B, because the English Note labels are used. The halftones are shown regardless of their harmony context as always with increased ♯ ( enharmonic ), sat '' would be written for example as F ♯ 5.
Especially in the digital notation, this simple notation has been established in tracker music programs, it is usually the only representation. Often a spectrum of C0 B9 is available via the standard keyboard ( A0- C8) continuous addition, although C0 16.35 Hz is the lower limit of the normal human audible range and B9 15.80 kHz is at the upper limit and no longer unique tonal can be determined. Theoretically, this notation, as well as the classic, in both directions can be extended.
Variants
The octave can occur in three variants:
- ( a) the pure octave is consonant and consists of 12 semitones.
As alterations added
- ( b ) the diminished octave with 11 semitones and
- ( c ) the excessive octave with 13 semitones
Which are among the dissonances and their designation as follows octave harmonic functional aspects. Join altered octaves between successive tones of different voices, it is called from a cross stand.
Clips
- Octave upwards? / I
- Octave down? / I