Banjo Rim Height and Sound in the Pot
  Rim and back geometry determine much of the behavior of sound inside the pot, whose effect on total, produced sound is subtle but discernible. The theory of sound inside a cylinder is reviewed and demonstrated. And previous work on the Helmholtz resonance and the interplay between the Helmholtz resonance and the lowest head mode is revisited using some improved techniques. 
David Politzer
physics.pop-ph