Geometric detuning effects are considered in this study of flow induced vibrations of the I nlet Guide Vane (IGV) row of the Purdue Transonic Compressor. The TAM -ALE3D fluid -structure interaction finite element code is used for the analysis, with the IGV and rotor rows modeled. The downstream rotor operating subsonically excites a trailing edge flapping mode in the IGV's. Two detuning strategies are evaluated: (1) decreasing the rotor -generated forcing function to the upstream IGV's, accomplished by detuning the rotor by unequal blade tangential spacing and (2) altering the IGV -rotor unsteady a erodynamic interactions, accomplished by detuning the IGV's by unequal tangential spacing. Evaluation of these strategies is quantified by the IGV unsteady aerodynamic modal force and internal IGV stresses. The unequal rotor blade row spacing produced li ttle change in the IGV stresses, while the unequal IGV row spacing was much more effective, reducing unsteady IGV stresses by a factor of six. Nomenclature