What is the relationship between phase and density

The answer is "a phase is a wave and density is what gives the wave its volume giving it its wavelength." Phases have different meanings for example phases of a moon and such but in this case phases are parts of mechanical waves that are closely related to each other meaning coming from the same object. So, with density is volume and because of volume it gives the wave its wavelength which is a phase. (when two waves are closely related)

Hope this helps!