A resonant frequency is a natural frequency of vibration of an object or a particle. It is the frequency at which the object vibrates generating a standing wave pattern. For any given instrument or object, there are usually several frequencies at which resonant frequency occurs. The lowest one among resonant frequency is called the fundamental frequency and is often denoted as f₁. An overtone could also be a term given to any resonant frequency above the basic frequency or fundamental tone.
The list of successive overtones for a given object is known as the overtone series. In this article, we will discuss what is overtone, harmonics and overtones and finally define overtone that will clear most of the concepts and confusions regarding overtones.
Harmonics and Overtones:
The term harmonic features a precise meaning - that of an integer (whole number) multiple of the elemental frequency of a vibrating object.
The term overtone is employed to ask any resonant frequency above the elemental frequency - and overtone may or might not be a harmonic. Many of the musical instruments of the orchestra, those utilizing strings or air columns, produce fundamental and harmonics. Their overtones can be said to be harmonic.
Other sound sources like the membranes (like drums) or other percussive sources may have resonant frequencies which aren't integer multiples of their fundamental frequencies. They are said to have non-harmonic overtones.
All harmonics are overtones for an open-air column or a string. A rectangular membrane produces harmonics, but also other overtones.
Another term sometimes used for these standing waves is overtones. The second harmonic is the primary overtone, the third harmonic is the second overtone, and so on. So, to define overtone, we can understand that overtone may be a term generally utilized for any higher-frequency stationary wave, whereas the term harmonic is reserved for those cases during which the frequencies of the overtones are integral multiples of the frequency of the elemental. Overtones or harmonics are also called resonances.
The first harmonic is the fundamental frequency. The second harmonic is twice its frequency, etc. Many instruments, especially bells, oscillate in modes that aren't whole-number multiples of the elemental frequency. These higher modes are called overtones. Overtones incorporate harmonics, but harmonics do not include overtones. Another confusing and important point is that the first overtone is not fundamental. The second harmonic is the first overtone.
In order to learn the concept of harmonics and overtones, we should first understand how they differ from each other. Let us have a look at some major difference between harmonics and overtones as listed below:
Difference Between Harmonic and Overtone:
Did You Know?
Few unique musical instruments among those whose sounds result from the vibration of metal, wood, or stone bars (for e.g., marimbas or xylophones) of cylinders (such as orchestral chimes) of plates (e.g., cymbals) or of membranes (e.g., drums or tabla) produce non-harmonic overtones i.e., the frequencies of the overtones are not multiples of the fundamental frequency.
Musical timbre, or tone colour, is suffering from the actual frequencies or the overtones favoured by a given instrument. The woody sound of the clarinet generated from its emphasis on low-frequency odd harmonics, whereas the more nasal sound of the oboe generated from the presence of all harmonics and a greater emphasis on the higher frequencies.