  We derive the asymptotic distribution of the null spectrum of the well-known
Multiple Signal Classification (MUSIC) in its computational Time-Reversal (TR)
form. The result pertains to a single-frequency non-colocated multistatic
scenario and several TR-MUSIC variants are here investigated. The analysis
builds upon the 1st-order perturbation of the singular value decomposition and
allows a simple characterization of null-spectrum moments (up to the 2nd
order). This enables a comparison in terms of spectrums stability. Finally, a
numerical analysis is provided to confirm the theoretical findings.
