3D20  Resonance in Strings
            .20 Sonometer
            .21 Guitar and Scope
3D22  Stringed Instruments
3D30  Resonance in Cavities
            .15 Resonance Tube with Piston
            .20 Resonance Tube
            .40 Helmholtz Resonators
            .60 Kundt's Tube
            .70 Singing Pipes
3D32  Air Column Instruments
            .10 Resonance Tubes (Three Lengths)
            .15 Slide Whistle
            .25 Open and Closed End Pipes
3D40  Resonance in Plates, Bars, and Solids
            .10 Xylophone Bars
            .11 Rectangular Bar Oscillations
            .12 High Frequency Metal Bars
            .20 Singing Rods
            .30 Chladni Plates
            .40 Drumhead
            .55 Glass Breaking with Sound
3D42  Percussion Instruments
3D46  Tuning Forks
            .16 Tuning Forks
            .22 Adjustable Tuning Fork
3D50  Electronic Instruments