Group {
    children [
        Shape { . . . }
        DEF C4 TouchSensor { }
        Sound {
            source DEF PitchC4 AudioClip {
                url "tone1.wav"
                pitch 1.0
            }
            maxFront 100.0
            maxBack 100.0
        }
    ]
}
ROUTE C4.touchTime TO PitchC4.set_startTime