Spherical Bells
The first shape then is a ball, or an approximation thereof, to represent a point source from which Sound proceeds in every direction. This can be discussed with a hand gesture like those used to describe volt, ohm and amp.
The first shape then is a ball, or an approximation thereof, to represent a point source from which Sound proceeds in every direction. This can be discussed with a hand gesture like those used to describe volt, ohm and amp.
The sleigh bell's internal clapper should be removed so that shaking doesn't work. So the bell must be suspended and struck. Point out that it can be heard from any position whether lying on the floor, sitting up or standing.
From any side, one can hear it.
The dexterity involved in sustaining the ring of a Baoding Ball is challenging because it requires that a person ring the ball and then hold it gently without grasping it and stilling the vibration. The bell and Baoning ball are analogous to the top and gyroscope presented in Motion. The bell and the top cannot be touched. The Baoding ball and the gyroscope offer a rigid frame that can be held.
From any side, one can hear it.
The dexterity involved in sustaining the ring of a Baoding Ball is challenging because it requires that a person ring the ball and then hold it gently without grasping it and stilling the vibration. The bell and Baoning ball are analogous to the top and gyroscope presented in Motion. The bell and the top cannot be touched. The Baoding ball and the gyroscope offer a rigid frame that can be held.
Flexible Tubes, PVC Tubes, Tubular Bells
Flexible tubing, all you have to do is spin it and the air inside vibrates. Speed and length change frequency.
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Just as reeds suggest woodwinds, rigid tubes suggest instruments, again with the problem of passing something from mouth to mouth. A classroom alternative is to clap a length of plastic tubing on the end. This vibrates the column of air inside producing a satisfying almost liquid sound. The shape of the hand varies the tone. Frequency can be varied by length and diameter of tube and by stopping/unstopping a hole drilled at a node or middle. The fact that you con hold the tube as tightly as you want makes it clear that it is not the tube which is vibrating.
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Tubular Bells
Most commonly seen in wind chimes tubular bells can be purchased as a set being a twelve semi-tone scale. Clearly these notes are sounded by vibrating the tube rather than the air inside it. All you have to do is touch a tube to stop it. Tubular Bells offer the opportunity to combine two accurate frequencies so creating an interval. The presentation of intervals is also the presentation of basic emotional effect characterized most clearly by the contrast between the major third and the minor third. |