Lab 3

• Read the documentation for the "make-tone" function. For all of the following, use a "volume" of 0.5 or lower, to prevent clipping (a.k.a. distortion).

  First, Define a sound containing two overlaid tones whose frequencies are separated by 4 Hz. Next, define a sound containing two overlaid tones whose frequencies are separated by 2 Hz. Finally, define a sound containing two overlaid tones whose frequencies are separated by 1 Hz. Do you hear a "beating" between the two tones when you play them? How is the rate of the beating related to the difference between the two frequencies? Write your observations in the form of a comment.

• Search the web to find the frequencies of the "C Major" scale from middle C up one octave. Define a sound that contains the notes of this scale, in sequence. See if you can avoid redundancy where possible.

• Write code that computes the interval (ratio) between each pair of adjacent notes in the scale. How many different intervals are present? Write your observations in the form of a comment.

  (Note: I’m not asking you to write a function, or to abstract over the repeated math. You can just go ahead and write seven little expressions.)

• Do HtDP 2e, exercise 31

• Do HtDP 2e, exercise 34

• Do HtDP 2e, exercise 40

• Do HtDP 2e, exercise 48. Write your findings in the form of a comment.

• Online, find a piece of sheet music for a song that you know. Use synth-note to translate at least four measures of the song into a racket program.

• Using big-bang, develop a program that plays a hi-hat every second. Read the documentation for the andplay function, which will be useful here.

• Extend this program so that its "state" is a boolean. When the boolean value is #true, the hi-hats play. When it’s #false, the hi-hat becomes a kick. When the user presses the space bar, the state toggles from true to false.