Harmonics and Overtones - What is the difference ?
I have noticed something slightly strange in the sound bath / sound healer scene. This is the over use of instruments that produce inharmonic overtones. These instruments include metal and crystal singing bowls, temple bells, gongs, crystal pyramids, tubular metal chimes and so on. I have heard a few of these healers talk about using musical intervals like fifths and major thirds to play more than one of these instruments together. This does not actually make sense though, because intervals only sound good with instruments that produce harmonics from the harmonic series. Playing musical intervals with instruments that produce inharmonic overtones is likely to cause discomfort in the listener, this in turn can bring up buried trauma in the listener. Using dissonance to bring up trauma is a part of the healing process, however, if the sound healer does not know how to produce harmony afterwards to heal the trauma, then the listeners will go home with more problems than they had before the sound bath !
I will explain the technicalities behind this...
I will explain the technicalities behind this...
Harmonics:
The first sound that we hear even before we are born is the human voice, this must be why our minds find the spacing between the harmonics in the human voice to be so pleasing. The spaces between the harmonics in the human voice are the same as those found in most musical instruments played by actual musicians. This arrangement of harmonics is called the harmonic series. Instruments that produce the harmonic series include the human voice, monochord, didgeridoo, piano, organ, harpsichord, violin, viola, cello, double bass, guitar, harp, flute, pan pipes, clarinet, oboe, bassoon, saxophone, trumpet, trombone, french horn, tuba etc. It is only the volumes of each harmonic that are different, it is these differences in the volume that gives each sound in own unique timbre.
Synthetic sounds made by combining, saw tooth, square, triangle waves and other similar wave forms are all based on the same harmonic series.
Each harmonic is a type of sound called sine wave, the most basic sound of all. The sine waves in a piano are exactly the same as the ones in a flute or any other instrument that produces the harmonics or overtones.
The harmonic series is easy to understand, the second harmonic is exactly double the frequency of the first one, the third harmonic is exactly 3 times the frequency of the first one, the fourth one is 4 times higher than the first one, and so on.
Our brains know this pattern so well that if you play a bass tone that contains higher harmonics, you can play a frequency much lower than you speakers can actually produce and it will still sound like it has that super low bass frequency. It works because your brain predicts the missing bass frequency and basically just adds it in as an imaginary sound. This is how well you know the harmonic series, it is almost like an instinct.
Our brains know this pattern so well that if you play a bass tone that contains higher harmonics, you can play a frequency much lower than you speakers can actually produce and it will still sound like it has that super low bass frequency. It works because your brain predicts the missing bass frequency and basically just adds it in as an imaginary sound. This is how well you know the harmonic series, it is almost like an instinct.
Musical intervals that share many harmonics sound good. The octave for example is the most consonant interval of all because every second harmonic in the lower note is the same as every single harmonic in the higher note (see image below).
The perfect fifth is the most consonant interval after the octave, in this one every third harmonic in the lower note is the same as every second harmonic in the higher note (see image below). The harmonics that do not line up still have good musical relations to with each other, but I will not get into that now because it is really complicated.
These intervals sound really good because the harmonics line up so well, this create a vibrational pattern that your brain finds easy to understand and process. This however only works with musical instruments that produce the harmonic series.
Overtones:
Some instruments don't produce harmonics from the harmonic series, these have overtones that are different for each instrument. Overtones and harmonics are not the same thing, harmonics have to be part of the harmonic series, while overtones can have any random position. Your brain does not know how to imagine missing overtones because they are different for each instrument.
Instruments that don't have harmonics include most metal and glass percussion instruments like church bells, hand bells, tubular bells, wind chimes, tam-tams (hanging gongs), temple gongs, tibetan singing bowls (or Himalayan bowls), crystal bowls, metal triangles, wave drums, lithophones and tuning forks. Basically all of the instruments used in sound baths.
These instruments grab your attention and can create tension, some them can be difficult to use in music because if the main frequency of the tone is in tune with the music then the overtones are usually not. In music they are used when needed but it is not common to compose entire pieces of using only these percussion instruments.
Instruments that don't have harmonics include most metal and glass percussion instruments like church bells, hand bells, tubular bells, wind chimes, tam-tams (hanging gongs), temple gongs, tibetan singing bowls (or Himalayan bowls), crystal bowls, metal triangles, wave drums, lithophones and tuning forks. Basically all of the instruments used in sound baths.
These instruments grab your attention and can create tension, some them can be difficult to use in music because if the main frequency of the tone is in tune with the music then the overtones are usually not. In music they are used when needed but it is not common to compose entire pieces of using only these percussion instruments.
Playing a musical interval like a perfect fifth or a major third with two of these instruments usually results in overtones that don't line up at all. This creates a vibration pattern that our brains find harder to process and can cause some discomfort to the listener. In this situation normal music theory does not apply because the sound being used in enharmonic and is not a normal musical instrument.
I did analyse a lot of sounds from sound baths and did notice that some of these instruments, particularly singing bowls, crystal bowls and tuning forks can produce fairly clean sine waves if they are played with a soft object. If you do strike them with a hard object, the overtones also usually fade out quite quickly leaving just the fundamental sine wave ringing for much longer. This is because the overtones don't resonate very well with the fundamental and end up dying off faster that it does.
The following image is a near perfect sine wave produced by a singing bowl that was played very softly with a mallet.
The following image is a near perfect sine wave produced by a singing bowl that was played very softly with a mallet.
So a bowl can be enharmonic or not depending on how it is played. When played softly you can avoid the overtones and gain more freedom when mixing different bowls together. When playing them hard you need to take into account what the overtones are doing. You do get very good sets of bowls that are selected to have matching overtones, these are ideal if you want to play more than one bowl together.
So if you want to be a sound healer, you really should understand dissonance and harmony and apply both of them in your work. Dissonant intervals and enharmonic sounds can be good to bring up trauma that needs to be healed, but to actually heal the trauma you need to understand music theory and how to create harmony.
So if you want to be a sound healer, you really should understand dissonance and harmony and apply both of them in your work. Dissonant intervals and enharmonic sounds can be good to bring up trauma that needs to be healed, but to actually heal the trauma you need to understand music theory and how to create harmony.
