Musical signals often present close frequencies producing beats and the classical Fourier Transform does not achieve a sufficient resolution to estimate these components separately with accuracy. This paper presents a spectral analysis technique for estimating and tracking the frequencies, damping factors and amplitudes of each component. SINTRACK associates a Matrix Pencil high resolution method with a LMS adaptive algorithm. It detects changes in the signal underlying model (as the changing number of sinusoids for example) and can indicate the time variations of parameters. Results are shown for a signal recorded from a guitar.