Sounds of Music

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Sounds of Music
Physics & Build Event
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2011 (C)
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Division B Champion Daniel Wright Junior High School
This event was not held last year in Division C

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 two durable, original, and creative instruments with which you will play two pieces of music. 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.


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


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.)


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


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)


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.

The Setup

When you arrive in the competition room, you will be at least 30 seconds, if not more, to set up. If you are ready in less than 30 seconds, you will receive a 5 point bonus. 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. There will be music stands where you may place your music, but other than that there is not much you can count on. 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 instruments you created, and the pieces you will be playing. Give the judges a score of the music you wrote at this time as well.

The Music

The required piece of music this year is the theme from the 2nd movement of Dvorak's New World Symphony. The basic melody, written in the key of C in treble clef, can found on the second page of the Sounds of Music rule sheet. You may alter this piece by transposing it to a key to fit your instrument but the instrument which plays the melody must play the same notes as provided on the rules, with no changes. You will also be expected to compose your own harmony to this piece, which the second instrument will play.

The second piece of music is completely your own creation. You may play anything you wish, from classical to pop to simple tunes like Twinkle, Twinkle, Little Star. It is best to play a song the judge will recognize. As with the required piece, you will need to write out your music with melody and harmony.

Concerning writing the music, there are a few requirements you must abide by. As mentioned before, the melody of the New World Symphony theme must be exactly what is written on the rules (though it may be in a different key). The music the higher instrument plays MUST be written in treble clef, and the music the lower instrument plays MUST be written in bass clef. Give the judges a copy of the music with both parts on the same page- you'll probably get it back later. Also make sure that your names, team name, and team number are on the music, since this is worth a couple points.

It is a good idea to write the music with music notation software. It looks more professional and has been recommended by judges at several competitions. Music software also makes sheet music easier to read, rather than what you may write by hand, no matter how good your handwriting is.

Some suggestions for music notation software are:

Technical Interview

The final portion of the event is the technical interview. It may be oral or written. In this section, you will have to explain how you built your instruments and how they work. You will also need to explain the sound theory behind your instrument and some of the physics of sound. BOTH team members will need to participate in the interview to get full marks.

The technical interview generally becomes more important as the year goes on (and the competition becomes tougher). This is because your opposition usually gets tougher as well and many more instruments sound 'real'. Because of this, the interview will become a huge separator of teams. Make sure you understand the physics of sound and wave theory, basics of resonance, basics of tempering, and go into as much depth as possible into how your own instruments function. Many people take this part of the competition lightly, but 30 points is nothing to scoff at.

This website provides much of the knowledge needed for the technical interview portion.

Rubric Overview

The highest score possible for this event, according to the rules, is 100. 20 points are awarded for the building and choice of instruments, as well as tuning, 20 points are awarded for being able to play the required scale, as well as sound quality, 20 points are awarded for the performance, 20 points are awarded for the technical interview, and 20 points are awarded for correct music notation, playing in the correct range, and being ready to be judged within 30 seconds of walking into the room.

Previous National Tournament Winners

Team Bass Instrument Treble Instrument
2007 Troy High School Guitar Trumpet
2008 Valparaiso High School Guitar Xylophone
2011 Harriton High School Marimba Flute
2012 Camas High School Marimba Violin

Instrument Instructions

Here are websites with tutorials to make instruments:

  • Woodwinds
    • [ PVC pipe penny whistle]
  • Strings
  • Brass