Lesson objective: By working with Sonic Pi, students will be able to accurately describe the characteristics of waves and the transformation of waves.
This lesson can be an exploration and review of sine waves.
First, brainstorm about waves, such as: what is a wave, discuss why a wave is useful, and then list all the important vocabulary of the waves, such as period Period, and amplitude:
The period of a function is the smallest domain containing the complete cycle of the function.
The amplitude of a function is half the distance between the maximum and minimum values of the function.
The frequency is the number of waves that pass a fixed point in a given amount of time.
Then review the general information on the graphs of sines, including what a sine graph looks like, the parent function, as well as the characteristics of the sine graph. Then make a connection between sine and a wave.
For example, the period of a sine or cosine function is the distance between the peaks of the graph.
Let students complete the Trignometry function Period amplitude table. The completed table is like this:
Note that the tangent wave has a vertical asymptote, so it has an undefined amplitude.
Main activity: A music wave clip in the Sonic Pi.
Before the group activity, conduct a whole-class discussion :
Play the Sonic Pi clip, and ask students, What kind of the wave is it? Sine, Cosine, or tangent?
Anticipated answers: Sine or Cosine. They are interchangeable with the additional transformation.
The anwer cannot be tangent.
set :bpm , 100
live_loop :boom do
use_bpm get(:bpm)
with_fx :reverb, room: 1 do
n = 60
amp = 2000
hwl= 10
play n, attack: hwl, release: hwl, amp: amp
sleep 0.1
end
end
Think - Pair - Share
First, students think individually about what each highlighted number mean.
If we make each number larger or smaller, what happens to the wave? Can we make each number negative?
Then they pair up to discuss and compare their ideas. They are going to write a paragraph to conclude their findings.
Finally, they are given the chance to share their ideas in front of the classroom.
Explain BPM means Beats per minute, it is one way to measure the frequency of the wave.
Listening Challenges - Watch the video and demonstrate how BPM affects a clip of music. Let students raise their hands up if they would like to stop so students are safe: Speedcore 100000 bpm
Explain amp controls the amplitude of the wave.
Explain attack and release changes in the wavelength/ period
Exit ticket: Make a mathematics model. Use the Sonic Pi interface Screenshot, and let students:
Make a sine and a cosine wave;
add the x and y-axis;
label key points;
label amplitude on each.
