The experimental and theoretical activity performed in the RFX device hasallowed a deeper insight into the MHD properties of the reversed field pinch (RFP)configuration. A set of successful experiments has demonstrated the possibility ofinfluencing both the amplitude and the spectrum of the magnetic fluctuations whichcharacterize the RFP configuration. A new regime (quasi-single-helicity states) wherethe dynamo mechanism works in a nearly laminar way and a helical core plasma is producedhas been investigated. With these studies a reduction of magnetic chaos has been obtained.The continuous rotation of wall locked resistive tearing modes has been obtained by anm = 0 rotating perturbation. This perturbation induces rotation of m = 1 non-linearlycoupled modes.