Introduction to Pitch

Sounds we hear occur when a moving object makes the air vibrate. These vibrations move through the air in the form of waves. The shape of the sound wave depends on the pitch of the sound.

Here's an example that might help you understand this:

1. Put a thick rubber band around a text book; making sure it lies flat.
2. Slide two pencils under that band so that one pencil is at either end.
3. Pluck the band gently between the two pencils.
4. Now move one pencil to the middle of the book; then pluck the band gently again; notice how the sound of the pitch is different.
5. When you pluck the whole band, the vibrations are slow so that you can easily see them. Slow vibrations give low sounds. When you pluck a shorter length of elastic the vibrations are faster, and faster vibrations give higher pitches.

To learn more about how sound works, please visit the following website:
Sound Is Energy (by Samuel Beckett & Jason Williams)

Musical Scale

Every sound has its own pitch, which can be high or low, depending on the shape of the sound wave. Each different pitch of sound makes a musical note. Musical notes are arranged in a special pattern called a scale. In this particular example, the sound wave of the pitch depends on the length of the elastic band that vibrates.

The musical staff is a type of graph. The vertical axis of the staff is pitch, or the highness or lowness of sound. The horizontal axis of the staff represents time.

In the previous subtasks, students learned the values of the musical notes and combined them in various ways to create rhythmic compositions. Students will learn in the next two subtasks that the musical staff is like a graph.

1. Have examples posted of different graphs. Discuss the information these graphs contain.


Guided Exploration
2. Create a contour graph with the students. Example:
   • Use squared graphing paper or the chalkboard to make a new graph with the students.
   • Conduct a quick survey. Who likes school? Responses can be either "Yes", "No" or "Sometimes".
   • Students raise their hands and can only answer once.
   • Record the student responses, then construct a bar graph to reflect student responses.
   
   
3. Discuss the horizontal and vertical axes of the graph, and how the taller bar indicates that a larger number of students chose that category. Compare this to the contour graph for "Frèrè Jacques" from Chart: Contour Graph for the Song "Frèrè Jacques" (which can also be seen in this photograph). Show how the vertical location of the notes on the graph indicates the range of pitch from high to low. Tell the students that each pitch is assigned a name. The horizontal location measures time.
Worksheets
4. Students are to create a contour graph for the first 8 to 10 bars of "Twinkle Twinkle Little Star", using Worksheet: Create a Contour Graph for the Song "Twinkle, Twinkle Little Star". They must shade in the correct squares. One quarter beat equals one square. For a half note, two squares should be shaded. (In Twinkle, "star," "are," "high," "sky," and "are" are half notes). When students are finished they can compare their work to Chart: Contour Graph for the Song "Twinkle, Twinkle Little Star" (which can also be seen in this photograph). They can play the song using xylophone or keyboard if available.
Guided Exploration and Worksheets
5. Discuss the contour or shape of the first two bars of Twinkle. Invite a student to draw it on the board. Play "Frèrè Jacques" or sing it. Invite the students to create contour graphs of the first two lines of other simple tunes, such as "Mary Had a Little Lamb," "Three Blind Mice," and "Rain, Rain Go Away" on Worksheet: Blank Contour Graph. Have them try out these songs on a xylophone or keyboard if available.

Intro | Subtask: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | Musical Terms | Examples

Developed by:	David deBelle (Mathematics)
	Anthony Micallef (Music)
(To contact by email, click on their names)