Demos by PIRA

  3D40.10Xylophone.
  3D40.20Longitudinal wave apparatus: Ball bounces off end of stroked rod.
  3D40.30Chladni's disc: Bowed disk forms patterns in sprinkled salt.
  3D40.31Chladni's Figures: Vibrational modes of a metal plate
  3D40.51Large glass bowl with ping pong balls and violin bow.
  3D40.55Beaker is broken by sound from speaker.