Overtone:
An overtone
is any frequency higher than the fundamental frequency of a sound.
Harmonics:
A harmonic
of a wave is a component frequency of the signal that is an integer multiple of
the fundamental frequency, i.e. if the fundamental frequency is f, the
harmonics have frequencies 2f, 3f, 4f, . . . etc. The harmonics have the
property that they are all periodic at the fundamental frequency, therefore the
sum of harmonics is also periodic at that frequency. Harmonic frequencies are
equally spaced by the width of the fundamental frequency and can be found by
repeatedly adding that frequency. For example, if the fundamental frequency
(first harmonic) is 25 Hz, the frequencies of the next harmonics are: 50 Hz
(2nd harmonic), 75 Hz (3rd harmonic), 100 Hz (4th harmonic) etc.
Harmonic
Series (In Mathematics):
In
mathematics, the harmonic series is the divergent infinite series.
Its name
derives from the concept of overtones, or harmonics in music: the wavelengths
of the overtones of a vibrating string are 1/2, 1/3, 1/4, etc., of the string's
fundamental wavelength. Every term of the series after the first is the
harmonic mean of the neighboring terms; the phrase harmonic mean likewise
derives from music.
Harmonic
Series (In Music):
A harmonic
series is the sequence of all multiples of a base frequency.
Pitched
musical instruments are often based on an approximate harmonic oscillator such
as a string or a column of air, which oscillates at numerous frequencies
simultaneously. At these resonant frequencies, waves travel in both directions
along the string or air column, reinforcing and canceling each other to form
standing waves. Interaction with the surrounding air causes audible sound
waves, which travel away from the instrument. Because of the typical spacing of
the resonances, these frequencies are mostly limited to integer multiples, or
harmonics, of the lowest frequency, and such multiples form the harmonic series
Octave:
In music, an
octave (Latin: octavus: eighth) or perfect octave is the interval between one
musical pitch and another with half or double its frequency. The octave
relationship is a natural phenomenon that has been referred to as the
"basic miracle of music", the use of which is "common in most
musical systems".[1] It may be derived from the harmonic series as the
interval between the first and second harmonics
The octave
has occasionally been referred to as a diapason.[2]
Octave chart for E Note on the Fretboard
Unison:
In music,
the word unison can be applied in more than one way. In general terms, it may
refer to two notes sounding the same pitch, often but not always at the same
time; or to the same musical voice being sounded by several voices or
instruments together, either at the same pitch or at a distance of one or more
octaves; or to rhythmic patterns which are homorhythmic.