Whole Class “ Just in Time” Instruction: To further assist students in building background knowledge about sound, Brian reviews three ideas about sound:
- How things make sound by vibrating and colliding with air.
- How sound travels as a compressional wave of energy through collisions in air particles.
- How the frequency and amplitude of sound waves result in differences in pitch and volume that we hear as qualities of sounds.
Brian strategically uses PowerPoint slides with images of sound as movement of energy through collisions of particles of air to help students work towards a compressional wave models of sound and to help students envision the difference between amplitude and frequency in compressional waves. In addition, Brian again brings out the Slinky toys to help act out various sounds. The Slinky image of sound waves continued to be a powerful learning experience for many students.
Revising Initial Music Models with Additional Science Content: Students use the last few minutes of class to revise their initial ideas about sound traveling from a musical instrument. Instead of having students write or draw on their posters directly, Brian has them add new ideas or revisions by writing or drawing on Post-It Notes. This allows Brian to quickly distinguish between students’ initial ideas and their subsequent revisions.

$C:\Documents and Settings\Jessica Thompson\My Documents\My Pictures\Microsoft Clip Organizer\j0431548.png$ Discussion Questions: 1) Which concepts has Brian chosen to emphasize at this point in the unit? Why? 2) How have students added science ideas to their initial models of sound? In what ways have students’ ideas changed? Are any students holding on to alternate explanations or ideas at this point in the unit? 3) How does Brian adapt his conversations with students depending on the level of understanding expressed by different groups of students?