Music consists of three, perhaps four, elements: rhythm, harmony, melody, and pathos, although the latter could be seen as an emotional response to music. Music is produced in various ways and for various purposes. Stringed instruments utilize vibrating strings, wind instruments utilize vibrating air columns, percussion instruments utilize vibrating diaphragms such as drum heads or solids such as bells, chimes, and even wooden blocks. Each of these instruments has its own vibrational signature that distinguishes the quality of sound. This enables one to identify the sound of a violin from that of a flute, even though they are playing the same note. The pitch of the sound is determined by the frequency of the longitudinal pressure wave, and the difference in quality is a result of the various combination of overtones.
The definition of sound has always been a matter of conjecture. There is the age old puzzle of whether a tree falling in a forest produces a sound if no one hears it. So, we must define sound here as the physical energy wave and not the sensation of hearing. We know that sound waves travel faster in solids than in air. Thus the expression 'keep your ear to the ground,' referring to the practice of American Indians who placed their ear to the ground to detect the distant hoof beats of approaching enemies, or the approach of a train by the sound traveling along the rails.
There are many sounds that we cannot hear; they are either of too high or too low frequency for the human ear to detect, however, we know they are there because they can be detected by instruments. For instance, ultrasound waves are used in medical research to penetrate into the body to observe internal body functions. Low frequency sonar waves are used in depth meters and in the underwater detection of ships, submarines, and schools of fish. Earthquake waves are felt rather than heard.
As we gaze in wonder at the starry heavens, the solar system of planets in their movements as precise as those of a watch, the stars that exhibit beauty of color and configuration, and the galaxies as they spiral in space, we can agree with the poet.
"What though no real voice nor sound Amid their radiant orbs be found? In reason's ear they all rejoice And utter forth a glorious voice, Forever singing as they shine, 'The hand that made us is divine.'" Joseph Addison, 1712.
Truly, this is God's great symphony in "the Music of the Spheres."
