This paper describes methods for the removal and/or separation of amplitude and frequency modulation of individual components within a Fourier spectrum. The first proposed method has a relatively low cost and works under assumptions about the behaviour of both the local and non-local magnitude and phase of sinusoidal components for these two forms of component nonstationarity. The second method is more expensive and resynthesizes components either in the Fourier or time domain following a parameter estimation stage. Typical applications are the adjustment of expressive parameters in music signals and conditioning of signals prior to cross-synthesis.