Sending shockwaves through speakers with its stomping drums, tightly wound synths and pulsating bassline, Fergie’s ‘Testify’ cultivates an atmosphere of anticipation so tantalizing you can almost taste it. Supercharging its sense of urgency with the ramped-up, euphoric synth stabs and an ecstatic vocal that calls the crowd to action, this track is the only reason fans need to crank it loud, shut their eyes, raise their hands and kick up some noise.