Sound or music comes to our ears by air molecules striking our ear membrane.
When one hits a drum, the drum membrane vibrates, sets to motion nearby air molecules, which by collision set to motion nearby air molecules until those near to our ear vibrate too.
This transfer of energy is called a wave. It is interesting that the energy flows not the molecules. Like sea waves, water is not transported it is the energy that does.
It is also interesting to note that even in complete silence molecules are random vibrating. The energy is ultimately coming as everything in our planet from coalitions of photos from the sun. It is called thermal motion and depends on temperature. When temperature of water for example is high water molecules vibrate so quickly that they can escape into air, the water boils.
We cannot hear thermal motion of air molecules (silence), because the sensitivity of our ear - brain mechanism is set just on this threshold. Otherwise life would be difficult hearing a meaningless hissing noise all the time.
Information occurs when something unexpected happens. When a someone sings a note or speaks the air molecules have an extra much larger superimposed vibration.
The simplest tone containing just one frequency is from a tuning fork that last infinite time.
Frequency in the number of complete cycles of a vibration occurring in 1 second (Hertz, Hz). A tuning fork vibrating 440 times per second has a frequency of 440.
It is the note A4, (la 4), the highest la that a man can sing.
An octave is a similar sensation but on higher or lower pitch. It is a close to a multiple of 2 but not exact. So the highest woman la would be somewhat higher than 880Hz. The confusion arouse because in electronic engineering it was found convenient to define an octave as an exact multiple if frequency.
Pitch and frequency are not the same, the first is the psychological impression the other is the objrctive measurement. Pitch obviously increases as frequency increases but also depends on intensity. For example if you listen to a YouTube clip containing a tone of 440Hz you will find that pitch drops appreciably as you increase the volume.
Electronic signals have many common with acoustic signals, the main difference is that instead of molecules we have electrons vibrating.
Electrons are so small that we cannot see, they have negative charge and have the peculiar property that when an electron in universe vibrates an electromagnetic field emmited makes another elceron in the universe vibrate similarly.
For example electrons in the sun make electrons in objects and in our eyes vibrate. Therefore we can witness and see beauty.
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The waves that make these happen are called electromagnetic and again it is not electrons that move but the energy that flows, furthermore they can travel through empty space.
Electronics is the part of art science and engineering that deals with the control of the movement of electrons.
Sound carrying air molecules striking the membrane of a microphone set in turn corresponding vibrations in the wire coil attached to it. So a microphone converts the vibration of molecules to similar vibration of electrons.
Vibrating electrons in a metal wire set into vibration the ones nearby and so on up to the other end. The wave is traveling and not the electrons. The electromagnetic wave is traveling at the speed light in the material the conductor is made of.
The tiny movement of electrons can be made larger. This is called amplification.
Electronic noise exists in conductors in the same way and it is the random thermal motion of electrons.
We can certainly hear this random motion as hiss if we turn up the volume in any amplifier when there is no music loud enough to mask it
In the beginning of the 20th century amplification was made possible by devices called electron tubes where the control of the movement of the electrons is done in the vacuum of the evacuated glass tube.
Since then smaller devices called transistors have been invented which have evolved to be so small that billions if them may exist in the processing chips of a smart phone.
The electron tube or vacuum tube faults make them very attractive to the production and reproduction of music.
Almost always tracing the origin of a hit song we will find more than one electron tube in the signal path from production microphone to the listener loudspeaker.. An obvious contemporay example is the use of the 1947 made Neumann U47 microphone having inside the VF14 electron tube. Such a mic can be seen for example in the Christina Anguilera video clip on recording Say Something.
A reason for tubes is the way they overload from a music signal mimicing the way our ear - brain overloads. There will always be overload as music is a tremendously dynamic signal and overload is a desirable thing compressing a large dynamic range to small so that one can hear loudly radio in the car without quite passages be masked by noise or louder ones overloading your laptop. The tube is made to overload so that the digital circuitry does not overload abruptly as it runs out of 1s. (11111111.... in a 16 bit coding digital system).
Music is the art and science of conveing emotions from the brain of the composer to the brain of the listener .
In practical terms it consists of melody, bass and harmony.
It consists of repetition and surprise but it's ingredients is melody bass and harmony.
((((( apendix on impedance
If an ant collides on a elephant, not much happens it may just bounce back. They have vastly different mass. In energy flow terms this is called impedance mismatching. A mismatch makes the energy being reflected back. Same when we look our selves to the mirror. Or if we talk with both palms in front of our nose on a non reflecting space like a beach.
If an elephant runs to collide with an ant again there is no much transfer of energy from the point that almost all of the elephants kinetic energy stays within the elephant and may put the elephant in danger if stopping in not done on time.
Difference in impedance is what make the waves bounce back at the end of a open organ pipe. Or reflect at the end of the guitar or piano string fixed at it ends. A similar reflection happens to the walls of a cathedral making the acoustic huge. Similarly as impedance mismatching mirrors on opposite walls make light waves echoes re reflect making the room look huge.
The trapped energy is called standing waves. In the strings the multiple reflections establish a repeating patern which produces the note we hear.
Strings can vibrate in may permissible modes. This produces harmonics.
Harmonics in turns produce the notes of the C major scale.
From 7 notes all music already existing and future can be made.
How we will shortly see. )))))
Melody is the mystery. We do not know where it comes from and it can happen to anyone whether musically educated or not.
Bass as the name signifies comes from the Greek basis meaning root or base and is the foundation of music where all harmony springs from it.[ JS Bach intructions to his students on figured bass]
Harmony is the combination of different notes sounding together.
Since there exist 7 only notes which repeat themselves at different octaves there will be 7 bass notes too.
The natural or common harmony when not something different is specified is produced by adding the 3rd and 5th (1 3 5 law) note on the right hand. So the bass being C. The right hand can be 1 3 5 ie C E G.
The most famous example would be opening chord of Imagine - John Lennon, bass being C and right hand using the notes C E G as a sequence of E G. Together then C then E G then C and so on to include a rhythm structure. Then after a while the bass becomes F and the natural law of 1 3 5 would r quire F A C, which is exactly what is done and this chord is called F major. Having a song with A on bass (second chord of Alone - Hearts) would require A C E. This time the chord is not called A major but minor due to the asymmetry of the keys of a piano. a to c has fewer semitones steps than c to E.
D on the bass naturally requires D F A an obvious example is the opening chord of Requiem in D minor. - Mozart.
Since there are 7 notes available for the bass there would be 7 chords that can be made (using the 1 3 5 law) and if we normalize any music piece to the C major scale ( using all white keys only we can play with both hands on a piano almost any musical piece ever written with just these 7 chords at the correct order the composer choose.
What makes the beauty of music further flourish is to depart intentionally from the 1 3 5 law to create further colors in our palette. A different code could be 1 4 7. An example is 2nd chord on Requiem - Mozart as the bass plays F and the right hand D A.
We can have many different codes and this is one of the reasons music can have an almost infinite variety even in its micro structure. Some of these combinations like 1 3 5 and 1 4 6 are called consonants and other are called dissonant such as 1 3 9. It does not mean that they do not sound agreeable. A beautiful example of 1 3 9 is third sung word of Close to You - Carpenters (in the sung word birds, the sung G is 9 notes above bass F) . Another example is the first chord of Just Hold Me - Maria Mena again a 9th chord.
Another example is the 3rd chord of Qui Tollis from Mass in B minor - J.S.Bach.
Much of the skillful art of music is the balance between consonants and dissonances as J.S. Bach explains and how 7ths and 9ths are prepared for our brain.
A useful rule is taking the third together with a 9th so 7th. An example is the 3rd chord of Bachs. Air where the bass plays G the right hand plays the prepared 7th note of the scale (D major scale in this piece) which is F# and the other instruments play th 3 rd B and D (5th). The reader us reared to the instructions to his students in music by J S BASS.
Orchestration being a subject in itself includes knowledge of masking theory.
An overlooked but extreme,y import knowledge to anyone involved into.making music is the knowledge of the Fletcher Manson curves. These show by experiment how the sensitive of the ear brain mechanism changes according to frequency and most importantly the intensity level of this frequency.
Having its practical origin to survival a very faint sound pressure level from a crying baby in danger emitting mid frequencies to the most sensitive mid range ear at low levels. The ear surging to catch up in sensitivity at low and high frequencies as iintencity levels increase. An obvious example is that by turning up the volume in a radio we start to hear not only louder but fuller, bass and treble perception coming to play.
If bass and treble frequencies are not reduced during recording or mid boosted by a high quality inductor equalizer the usually higher intensity in reproduction will make a voice sound bassy boomy and spitty due to bass and high frequency predominance compared to mid range.
Although it is easy to assume that one must record and reproduce flat it proves that one has to deliberately make a mistake to to counteract natures "mistake " so that the correct natural and pleasing balance results.
This may seem contradictory to signal theory requiring that flat reproduction will produce an undistorted signal. This would be true if our signal path would be from production microphone to reproducing loudspeaker.
Actually the signal path is from the vocal chords of the performer to the brain of the listener or the brain of the composer to the brain of the listener.
So we have in our disposal all those molecules of air and electrons to tell them what they should do.
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