In normal (as contrasted with multiphonic) woodwind tone production, the nonlinear flow control characteristic of a reed transfers energy between components of the spectrum by heterodyne action. The frequency of oscillation is that which maximizes the net oscillatory energy production by suitably matching several spectral components to input impedance peaks whose frequencies are in an approximately harmonic relationship. The resulting spectrum is strictly harmonic. So-called “multiphonic” tones are produced by a generalization of the same process. A typical multiphonic tone is sustained by the reed's collaboration with (for example) three reasonably strong input impedance peaks lying at frequencies fp, fq, fr These peaks have no harmonic relationship. The sound spectrum is made up exclusively of heterodyne components of the form αP ± βQ, μP ± νR, etc., where P, Q, R are the basis components (α, β, etc., integer). Here P ≃ fp, Q ≃ fq, R ≃ fr, the exact values being those which give the largest net oscillatory energy input over the entire spectrum. Unambiguous correlations of oscillatory regimes made up of up to 25 spectral components have been made. Examples are given showing the interpretation of several multiphonic tones on the oboe and clarinet.