1. Standing Waves Destructive interference Constructive interference

2. How a standing wave results from interference of two waves
A standing wave is the result of the interference of two identical waves that are in phase at the anti-nodes and out-of-phase at the nodes.
Incident wave direction
Reflected wave direction
Standing wave
Destructive interference at the node (out-of-phase)
Constructive interference at the anti-node (in phase)

3. Music and Standing Waves
Tones produced by musical instruments are caused by standing waves of different harmonics
Wavelengths must fit within space
Wavelengths do not fit—not a standing wave

4. Harmonics are standing waves that increase in the number of wavelengths in a predictable pattern