Wade Blocker The Theory of the Edgetone Oscillator (76K, tt) ABSTRACT. The resonant acoustic column of such musical instruments as the flute is not necessary for a tone to be produced. A tone results when a jet of fluid is blown against an edge. Past efforts to explain this edgetone oscillator have been unsuccessful. The assumption that the edgetone oscillator is an acoustic transit time oscillator closely analogous to electronic oscillators leads to a theory in almost exact numerical agreement with all critical experimental data.