In this chapter we start with resonance on a string and then look at resonances on two dimensional surfaces. A brief introduction of three dimensional resonance in an enclosed volume is given and will...In this chapter we start with resonance on a string and then look at resonances on two dimensional surfaces. A brief introduction of three dimensional resonance in an enclosed volume is given and will be expanded on in Chapter 16 on Acoustics. Once the basic behavior of waves on a string, surfaces and in an enclosed volume are examined we look at how these principles end up explaining how stringed instruments such as guitars and violins work.