Sounds of Music

Sounds of Music is an event in which two participants build two homemade instruments, play two songs in a performance taking up less than 180 seconds, and explain the physics of sound through an interview and/or written test.

The Instruments
The main part of Sounds of Music is the building of the instruments. You will need to build one durable, original, and creative instrument with which you will play a scale. You will also need to answer questions about the theory of your instrument and how you built it.

Building an Instrument
For 2013's competition, participants are required to build two instruments of any type, barring electrophones. The instruments must be played in such a way that all energy put into the instrument to make a sound must originate from the team.

When building your instruments, you'll have to be creative. No commercially available instrument parts are allowed, (i.e. mouthpieces, mallets) excepting strings. Experiment with different materials. PVC pipe is a common material that is cheap and easy to make into an instrument; PVC pipe aerophones are very common.

Other instruments very commonly made include idiophones (xylophone, marimba, etc.). You will also want to experiment with materials if you are building one. Try different types of metal pipes and different types of wood to see what works best. There are several resources online that will give you the exact length to build the bars, but you will need to fine tune these so you get the exact pitch.

When building a idiophone or other percussion instrument that is hit, you will also need to consider the material with which you build the mallets. If you use a soft material such as rubber or yarn, the percussion instrument could be drowned out by a wind instrument. If you use harder materials, the instrument will have a harder, clearer tone, but the tone quality may suffer. Once again, you'll have to experiment to see what suits your playing style best.

Remember that your instruments MUST be in the allowable range. One instrument will be in the bass clef range (G2 to G3) and the other will be in the treble clef range (C4 to C5). It is not uncommon for teams to get knocked down a tier or two because they are in the wrong octave.

See this page for more about determining pitch.

There are four basic classifications of instruments under the Hornbostel-Sachs system as shown below. The fifth, electrophones, was not included for several years after the creation of the Hornbostel-Sachs system and is not used in competition.

Idiophones
An idiophone is a instrument in which the vibration of the instrument itself is what creates sound. They are generally the percussion instruments that are hit, shaken, or rubbed to create sound. Resonators can also be added to these instruments to create a sound.

In this event, the major type of idiophones created are xylophones, marimbas, or chimes. When you double the length of a bar, you cut the frequency in a fourth (put it down two active octaves). So in these instruments, to go down an increment of the scale, you must decrease the note length by a factor of the 24th root of 2. These also require you to fine tune (sand/file).

Examples of idiophones include
 * Xylophones
 * Bells
 * Steel Drums
 * Wine Glasses

Membranophones
Membraphones are instruments which have a vibrating membrane over a resonator to create sound. These instruments are generally harder to build and perfect.

Examples of membranophones include
 * Tuned drums
 * Timpani
 * Kazoo (this is edgy and depends if the judge feels like it is within boundaries. You would also need to be able to hum in perfect pitch.)

Aerophones
In aerophones, sound is produced by a vibrating column of air within the instrument. The air is usually produced in one of two ways: the player directs wind towards a sharp edge, creating an oscillating wind going in and out of the pipe; or, the player buzzes his/her lips against a mouthpiece, creating a vibrating column of air that goes into the pipe. The wind that goes into the pipe vibrates, creating a sound wave. Pitch is changed by the changing size of the column of air.

Examples of aerophones include
 * Flutes
 * Pan Flutes
 * Tubas
 * Trombones
 * Horns/Trumpets

Chordophones
In chordophones, sound is produced by a vibrating string. The vibration of strings produces standing waves producing fundamental frequency as well as harmonics (the relative abundance of these make up the timbre of your instrument). Resonators added to the string will enhance the sound by vibrating sympathetically with them.

In chordophones, the wavelength made is twice the length of the string. Since we know that velocity equals frequency time wavelength, after assuming that the velocity of sound in the string will remain constant, we find that when one doubles length, frequency will be cut in half (note goes down an octave). Because the relationship between length and frequency is exponential we know that for every increment one goes up in a scale (1/12), the note increases by a factor of the 12th root of two. You can use this fact for starting your tuning. Unfortunately, you'll need some fine tuning and many hours to get your instrument to play accurate notes due to imperfections in string and to the fact that there will be different amount of tension on different strings (when playing different notes on single guitar string, there will be different amounts of tension). This will result in different velocities of sound in the string, making this form of tuning less reliable.

Examples of chordophones include
 * Guitars
 * Violins
 * Harps
 * Zithers
 * Lyres
 * Piano/Harpsichords (on the harder side to make, not advised)

Electrophones
NOTE: Electrophones are not allowed under the rules for 2013.

Concerning electrophones, sound is produced by an electrically powered oscillator. It is highly unlikely anyone will build this type of instrument for Sounds of Music anytime in the near future, and it is also barred from competition under 2013 rules.

Examples of electrophones include
 * Theremins
 * Synthesizers

The Competition
While much of the work for the Sounds of Music event takes place before the competition, in the form of building, tuning, and practicing, only one part actually counts for Science Olympiad, and that is the competition.

This section is not a replacement for the Science Olympiad rules manual. Please read the Science Olympiad rules manual to get exact and official descriptions of each section.

The Written Test
The most points are given for the written test. In a separate room from the instrument testing area, you will have at least 20 minutes to complete at least three questions from each topic:


 * 1) Principles of acoustics
 * 2) Science terminology involving sound and its production
 * 3) Fundamental elements of musical sound; perception of it; resonance
 * 4) Design and function of instruments
 * 5) Notes, scales, and intervals (music theory)

The Setup
When you arrive in the competition room, you will be at least two minutes, if not more, to set up. This normally isn't a problem, as most instruments are mounted or otherwise ready to play. Some teams do bring xylophones that are not mounted or otherwise connected, and these teams will likely use the majority of the time. The room will likely have very few resources. Some competitions may provide a table or desks to place xylophones on, but it may be smart to bring your own portable table just in case.

During the setup time, introduce yourself to your judges. Provide information such as your name, your school name, the type of the instrument you created, and the scale you will be playing.

The Scale
The main testing component will be a pitch score test. You must play a major scale - any major scale - and hold each note for five seconds. If you wish to skip any notes, you must declare that beforehand. You will be scored per note. Multiple attacks on each note are allowed, and the closest pitch on each note counts for the score.

The Volume Test
The volume score test will involve playing a single note from your scale for five seconds. Multiple attacks are allowed. The highest volume in decibels at a distance of one meter will count for the final volume.

The Log
The last portion of the event is the log score. You must submit logs containing a list of materials used, a chart showing how you tuned (with at least 5 data points), proper labeling, and a diagram that shows how the instrument is played.

Rubric Overview
The highest score possible for this event, according to the rules, is 100. 36 points are awarded for the building and choice of instruments, as well as tuning, 10 points are awarded for logs, 9 points are awarded for having a loud instrument, and 45 points are awarded for the written test.

Instrument Instructions
Here are websites with tutorials to make instruments:


 * Woodwinds
 * [www.ggwhistles.com/howto/LowTechWhistle.pdf PVC pipe penny whistle]
 * Strings


 * Brass


 * Percussion
 * Xylophones
 * Steel Drum