Hosted by: UT Austin Engineering Chamber Orchestra
Visit our Booth: Saturday, February 27, 2021, 12 p.m. - 4 p.m.
Recommended Grades: 4th, 5th, 6th
The Challenge: Create your own musical instrument and learn about the science behind sound!
- 2 jumbo craft sticks
- 1 regular drinking straw
- 1 wide rubber band (#64 size)
- 2 small rubber bands
- Stretch the wide rubber band around 1 jumbo craft stick lengthwise.
- Cut 2 pieces of straw, each about 1 inch long.
- Put 1 straw piece underneath the rubber band, about 2 inches from the end of the stick.
- Put the other straw piece above the rubber band, about 2 inches from the opposite end of the stick.
- Place the second jumbo craft stick on top, lined up with the first stick below.
- Wrap 1 small rubber band around the two sticks to pinch them tightly together, about 1/2 inch from the end of the stick.
- Wrap the other small rubber band around the two sticks, 1/2 inch from the opposite end.
Place your mouth in the middle, between the two straws, and blow through the sticks. This is similar to playing a harmonica! You can experiment by moving the straws closer together or farther apart or by blowing harder or softer. The sound you get will change.
Share a video of you playing a concert with your musical instrument on Flipgrid.
Follow along as we demonstrate the activity and discuss some of the science behind sound in the video on the Activity Video tab!
Sounds are made by vibrations. Blowing into the Sound Sandwich makes the large rubber band vibrate. This vibration travels through the air and is heard by your ears.
Pitch is a property of sound that we hear as how high or low a note is. Pitch is related to the speed of the sound vibrations. Faster vibrations make sounds that are higher in pitch.
You may notice that moving the straws closer together makes sounds that are higher in pitch. This is because the part of the rubber band that can vibrate is now shorter. A shorter rubber band vibrates faster, which means that the pitch is now higher.
Blowing harder also makes a sound with a higher pitch. When you blow harder, the speed that you force the rubber band to vibrate at is faster. This will increase the pitch as well.
How does this activity connect to STEM and today's Girl Day theme of Designing Fun: Theme Parks, Games and Music?
Engineers have to understand how sound works in order to develop technologies that use the properties of sound. This applies to building musical instruments and designing concert halls or even to making medical equipment, such as ultrasound scans. Knowing the science behind sound helps engineers choose materials and designs that
Follow along as we demonstrate the activity and discuss some of the science behind sound!
The Engineering Chamber Orchestra (EChO) is an organization open to all musically inclined students, faculty, and staff throughout The University of Texas at Austin. We are housed in the Engineering school, but open to all majors!
Our mission is to preserve musical interest and appreciation by encouraging our members to promote music in the community. We offer members the opportunity to participate in unique chamber ensemble experiences and a casual, fun orchestra not found anywhere else on campus.
EChO members rehearse a variety of music in ensembles of two to five members and/or a chamber orchestra. At the end of each semester, they have the opportunity to showcase their efforts in a public concert series. Members also have opportunities to promote music by teaching kids about the science behind music and performing at nursing homes.
Founded in the fall of 2009, EChO was immensely popular from its inception, with 70 new members grouped into small ensembles. In the spring of 2013, EChO started its first ever orchestra with only 13 string players.
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