Presented on Tuesday at IMAC some of the new results I obtained using control-based continuation (CBC) on a nonlinear system with harmonically coupled modes. It is one of the first demonstration of CBC on a system with multiple degrees of freedom. Figure 1 shows CBC allowed to uncover the presence of an isola (a curve of stable periodic responses disconnected from the main resonance peak). Isola can easily be missed by classical testing methods and lead to a significant underestimation of the resonance frequency and amplitude.