The inhomogeneous anisotropic interactions of solids under MAS of slow rotation break up the NMR spectra into a series of spinning sidebands which contain all the information about the interaction tensors. This structural useful information can be extracted by computing and analysing only a few of ths sidebands. This method ,which is applicable for various inhomogeneous interactions and is based on an expansion of the Bessel functions using the irreducible spherical tensor and operator representation of the spin interactions, is reported in the paper. The experimental spectra of typical samples dominated respectively by chemical and quadrupolar interaction agree well with the theoretical ones.