Music can loosely be defined as organized sound. The lesson objectives, understanding sound is a form of energy, understanding pitch, understanding sound traveling through a medium, and being able to separate music from sound, can provide a good knowledge base as to how sound, math, and music are related. Sound exists everywhere in the world; typically objects cause waves of pressure in the air which are perceived by people as sound. Among the sounds that exist in everyday life, a few of them produce a definite pitch. For example, blowing air over half full glass bottles, tapping a glass with a spoon, and tapping long steel rods against a hard surface all produce a definite pitch because a certain component of the object vibrates in a periodic fashion. The pitch produced by an object can be changed by the length or the volume of the portion that vibrates. For example, by gradually filling a bottle while blowing across the top, higher pitches can be generated. By organizing a few of these sounds with a clearer pitch, the sounds become closer to music. The very first musical instruments involved using various objects (e.g. bells) that have different pitches, which are played in sequence. The organization of the pitches is what transforms sounds into music. Since the first instruments, the ability to control pitch has greatly improved as illustrated by more modern instruments such as guitars, violins, pianos, and more. Music is comprised of organized sound, which is made of specific frequencies. This lesson will help define and elaborate on the connections between sound and music.

Engineers must understand the relationship between pitch and the natural frequency of various materials to design instruments that produce beautiful music. Sound Music Vibration Frequency Wavelength none Students should be able to explain that sound is a form of energy Students should be able to explain the relationships between pitch, frequency, and wavelength (as frequency increases, pitch increases, and as wavelength increases, pitch decreases) Students should be able to list different media through which sound waves can travel Students should be able to explain that music is the organization of sound The most entertaining way to introduce the lesson would be to provide some sort of musical performance whether it is a recording of a concert they listen to through a compact disc player, a short video of a musical performance, or maybe even the teacher playing an instrument. Understanding something audible that is clearly music and then separating it into individual sounds is the goal of the lesson. Some useful materials to talk about during the lesson: glass bottles, tuning fork, some sort of stringed instrument if possible (e.g. a guitar, violin) Ask what the difference between sound and music is. A tuning fork can be a useful tool to demonstrate sound transmission. The fork is hit with the hand, generating a tone. By touching the fork to something wooden and hollowed out, the air inside the wood vibrates and the pitch generated by the tuning fork is greatly magnified. Show the demonstration of the tuning fork after playing an example of a performance. Get the students to speculate about why the sound gets louder. Ask the students about how they think stringed instruments change pitch. Bring a few glass bottles and fill them with varying amounts of water. Blow across the tops of the bottles and ask the students why they think the bottles make different sounds. When an object is struck, it can vibrate with a certain frequency. The particular sound the object makes when struck is a direct result of the frequency at which it vibrates. A good example is hitting a glass bottle that has water in it. Certain things can affect the frequency at which an object vibrates at. With something like a guitar string, the tension of the string, the thickness of the string, and the length of the string all affect the frequency. Anything that makes the object vibrate faster will increase the frequency and thus increase the pitch that an object produces. The vibrations can be graphed if so desired. The result is something of a "squiggly" wave, also known as a sinusoid. The peaks are called crests, the valleys are called troughs, and the wavelength is the distance from one point on one cycle of a wave to the corresponding point on another cycle of the wave. Wavelength is inversely proportional to frequency - as wavelength gets bigger, the lower the frequency (and fewer vibrations per unit of time) at which an object vibrates at. The sounds caused by objects can therefore be somewhat controlled. In the case of a stringed instrument, the sound can be very carefully controlled. These sounds with particular vibrations can be organized and played in sequence to make music. The water filled glass bottles would provide evidence of this as simple songs can be learned on the bottles. This method of sound manipulation is the basis for many instruments, which should demonstrate how sound and music correlate. Vibrations transmitted through a medium, with frequencies in the range capable of being heard by humans Organized sounds A rapid motion of a particle or solid about central position. The number of complete cycles of a periodic process occurring per unit time. Distance between two consecutive "peaks" or between two consecutive "valleys" in a series of waves. Strum Along One way to demonstrate this is to make a simple recording on a cassette or a compact disc of various sounds as well as clips of music and have the students vote on which audio clips are sound and which audio clips are music The students should indicate that the shortening of what vibrates (string) leads to a higher pitch In the case of the glass bottles, since the column of air inside is what vibrates, shortening the column (adding water) makes the sound produced by blowing across the top higher in pitch The tuning fork provides a good example of this fact. Additionally, any stringed instrument versus just a piece of string shows this fact because the string by itself does not produce much sound; therefore, the string transfers the sound to the body of the stringed instrument which then vibrates, causing the air to vibrate and make sound. Sound can also travel thru water (e.g. whales communicate using sound) If the students can use the example with glass bottles filled with liquid and propose a rule for how the sound made by the bottle changes (more water=higher pitch), then the students understand one of the main goals. The same goes for a stringed instrument if one is available during the lesson. Completion of the associated activity, Strum Along, will also demonstrate understanding of the principles in the lesson.