Final answer:
In an instrument out emergency, your instructor will most likely cover the air inside the guitar, the air surrounding the guitar, and the ground beneath the musician.
Step-by-step explanation:
When a guitar is played, the movement of the strings creates vibrations that travel through the air inside the guitar, creating sound waves.
These sound waves then interact with the air surrounding the guitar, as well as the ground beneath the musician, which can affect the acoustics and resonance of the sound produced. So, In an instrument out emergency, your instructor will most likely cover the air inside the guitar, the air surrounding the guitar, and the ground beneath the musician.