In this paper we present a new Analysis/Synthesis method named SINOLA, which benefits from both sinusoidal additive model and OLA/PSOLA method, and which allows adequate processing according to the inherent local characteristics of the signal. All the parameters of the models are derived at the same time from spectrum analysis. We propose an analytical formulation of a Complex Short-Time Spectrum Distortion measure, which allows the retrieval of precise sinusoidal parameters as well as their slopes. A new partial tracking method is proposed which benefits from these informations. Reassigned Spectrum is used in both time and frequency in order to characterize the signal and to position the PSOLA markers.