Video 1. Helmholtz string wave excited by slip-stick mechanism of moving bow (University of New South Wales, courtesy of Joe Wolfe).
Video 2. Visualisation of empty shell modes in vacuum before opening f-holes or adding bass bar. Ribs are transparent to view back plate vibrations as well as top.
Video 3. Empty shell modes with open f-holes at twice normal ambient pressure. The circular disc moving up and down represents air flowing in and out of the f- holes.
Video 4. Shell modes without bass bar but with a 20 mm offset sound post to illustrate asymmetry of resulting shell modes and coupling of breathing mode to previously non-radiating modes