In the next few years a suite of new facilities will start observing the radio sky with fields of view, sensitivities and bandwidths which have not been available before. Some observatories will explore the low-frequency radio sky down to tens of Megahertz with unprecedented sensitivity and high spatial, spectral and temporal resolution. I will discuss the synergy of these new radio telescopes with Fermi and what we can learn from observing some of the most extreme objects in the Universe at the two extremes of the electromagnetic spectrum.