The lowest resonant frequency of a tube or string is the fundamental. The higher ones are overtones, and all of them are called harmonics. All resonant frequencies are whole-number multiples of the fundamental; a plucked string makes pulses that travel both ways, and because its ends are fixed, nodes appear at the ends and a standing wave forms. The same idea works inside a tube. A tube open at both ends has a fundamental frequency twice what it would have if closed at one end; a tube closed at one end has only odd multiples of the fundamental, while an open tube also has the even ones, so an open tube sounds richer. The low register of the clarinet has mainly odd harmonics.
The violin emerged in northern Italy in the early sixteenth century. The oldest documented violin with four strings was made in 1555 by Andrea Amati. On a violin the bridge transfers some of the string's vibration energy to the body, and the body pushes air because it has a large surface area; the belly, the top plate, is the most important part of the body for pushing air. A small post inside the violin connects the flexible belly to the stiffer back and helps keep the belly from collapsing under the string tension. The air inside the violin's body is important, especially for the low range; the more complex the shape of a sounding box, the greater its ability to resonate over a wide range of frequencies.
The eardrum vibrates from sound waves and sends the vibrations to three tiny bones in the middle ear. People can hear sounds from about 20 to 20,000 hertz. Hair cells near the wide end of the cochlea detect higher-pitched sounds, and those closer to the center detect lower-pitched sounds. Vibrations make fluid in the snail-shaped cochlea ripple, and hair cells there bend and make electrical signals. Doubling the power of a sound adds 3 decibels, yet doubling the power does not make a huge difference to the loudness. Most noise-induced hearing loss comes from damage and death of hair cells, and human hair cells do not grow back.
Erich von Hornbostel and Curt Sachs published a system for sorting instruments in 1914. The 1914 system had four classes: idiophones, chordophones, membranophones and aerophones. In it, an idiophone is an instrument whose own body vibrates, often by being struck, a membranophone is one in which a membrane or thinly stretched material is vibrated, and an aerophone is one in which vibrating air produces the sound. In 1940 Sachs added a fifth class, electrophones, whose sound is made by electrical means. Organology is the science of musical instrument classification.
An African talking drum has two drumheads joined by cords. The drummer squeezes the cords to change the pitch and mimic the tones of speech. Drums can be struck, rubbed, as with friction drums such as the cuica, or played by a string attached to the head; a drum body acts as a resonant cavity: a frame drum with no enclosure sounds loud but lacks depth, while a bigger enclosure gives a fuller, deeper sound. Like a string, a drumhead gives a higher pitch when its tension goes up.
Bartolomeo Cristofori, who worked for the Medici family in Florence, Italy, built the first piano in the early 1700s. In 1850 Antonio Torres Jurado refined the guitar in its most significant breakthrough. George Beauchamp patented the electric guitar in 1936, and electromagnetic pickups change the vibration of the steel strings into electrical signals; a piano hammer must rebound at once after hitting the string, so the string is left to vibrate freely. Cristofori's hammers were covered in deer leather and hit the strings from below.
The Leipzig Gewandhaus Orchestra was organized in 1781 from a merchants' concert society. The orchestra grew bit by bit from 1600 to 1900 but changed very little during the twentieth century. A modern orchestra's string section has 16 to 30 violins, 8 to 12 violas, 8 to 12 cellos and 5 to 8 double basses. Every orchestra section has a principal who generally leads the group, and the principal first violin is called the concertmaster.
In a double-blind test, neither the players nor the people handing them violins could know which was which. Of 21 professional violinists, only 8 chose an old violin to take home, and one of the new violins was chosen most often. The Stradivari family of violin makers of Cremona lived from 1644 to 1737. In 1995 people in Slovenia found a juvenile cave bear's thigh bone with a line of small holes. As of 2026 scientists still disagree about how the Divje Babe holes were made: by people or by ice age hyenas.
In 1977 NASA sent two Voyager spacecraft into space, each carrying a gold-colored record of Earth's sounds and music. The first piece of music on the record is the first movement of Bach's Brandenburg Concerto No. 2. Carl Sagan was asked by NASA to chair a committee that gathered images, sounds and songs to represent Earth. Alan Lomax suggested fifteen of the twenty-seven performances that were launched with the Voyager probes. The record carries the first movement of Beethoven's Fifth Symphony and the Queen of the Night aria from Mozart's The Magic Flute. It also holds greetings from earthlings in 55 different languages.
The Minimoog was the first synthesizer sold in retail music stores, and it let keyboard players compete with guitarists in solos. Robert Moog's 1964 paper described the foundation for a voltage controlled oscillator, which many later synthesizers built on. Robert Moog was fascinated by the theremin as a boy and built his first from plans in the magazine Wireless World. On a theremin the player's hand and an antenna form the two plates of a capacitor. The other hand controls volume: the closer it is to the horizontal loop antenna, the lower the volume.
Words to know
- fundamental: lowest frequency
- harmonics: overtone family
- organology: instrument science
- electrophones: electric instruments
- cochlea: ear's snail shell
- theremin: hands-free instrument
