We present the real-time VME system used to detect and track MHD instabilities, and particularly Alfvén Eigenmodes, on the JET tokamak. This system runs on a 1kHz clock cycle, and allows performing a real-time, unsupervised and blind detection, decomposition and tracking of the individual components in a frequency-degenerate, multi-harmonic spectrum, using a small number of input data which are un-evenly sampled in the spatial domain. This makes it possible to follow in real-time the detected modes as the plasma background evolves, and measure in real time their frequency, amplitude, toroidal mode-number and damping rate. The successful implementation of this system opens a clear path towards developing real-time control tools for electro-magnetic instabilities in future fusion devices aimed at achieving a net energy gain, such as ITER.