Glossary
Acoustics
Glossary
The study of the science of mechanical vibrations is called acoustics. To help understand music theory, it is useful to understand the relationship between pitch, the fundamental tone, and overtones, which may or may not be harmonics, or integer multiples of the frequency of the fundamental tone.
A string (on a guitar or a piano, for example) vibrates in multiple different ways (partials) at the same time, at multiple frequencies. The lowest frequency is called the fundamental tone, which is also the first harmonic (one times the fundamental frequency). On many instruments the next tone is twice the fundamental frequency, the first overtone or second harmonic, one octave above the fundamental. The next frequency is the second overtone or third harmonic, approximately one just perfect fifth plus an octave above the fundamental.
Timbre refers to how strong each overtone is relative to the others and to the fundamental, making a given instrument uniquely identifiable. The harmonics continue, eventually dropping off in strength. Other intervals are present (subtracting out octaves), including a second octave above the fundamental, then a just major third, another octave, a major second, another just major third, etc.
If you start with a root note and keep track of which of the notes of the 12-TET chromatic scale is closest to each of these harmonic intervals, then rearrange them to form a scale, you eventually arrive at the notes of the Lydian dominant or acoustic mode. (See acoustic scale for the unordered scale that contains the seven modes, including the acoustic and melodic minor modes.)
The study of the science of mechanical vibrations is called acoustics. To help understand music theory, it is useful to understand the relationship between pitch, the fundamental tone, and overtones, which may or may not be harmonics, or integer multiples of the frequency of the fundamental tone.
A string (on a guitar or a piano, for example) vibrates in multiple different ways (partials) at the same time, at multiple frequencies. The lowest frequency is called the fundamental tone, which is also the first harmonic (one times the fundamental frequency). On many instruments the next tone is twice the fundamental frequency, the first overtone or second harmonic, one octave above the fundamental. The next frequency is the second overtone or third harmonic, approximately one just perfect fifth plus an octave above the fundamental.
Timbre refers to how strong each overtone is relative to the others and to the fundamental, making a given instrument uniquely identifiable. The harmonics continue, eventually dropping off in strength. Other intervals are present (subtracting out octaves), including a second octave above the fundamental, then a just major third, another octave, a major second, another just major third, etc.
If you start with a root note and keep track of which of the notes of the 12-TET chromatic scale is closest to each of these harmonic intervals, then rearrange them to form a scale, you eventually arrive at the notes of the Lydian dominant or acoustic mode. (See acoustic scale for the unordered scale that contains the seven modes, including the acoustic and melodic minor modes.)