The chanting is only just beginning to die down as Rodimus assaults Soundwave, and with his attention occupied by gazing furiously at Orion it's a few long moments before Megatron notices. But the fact that Rodimus is able to make this move at all, rather than being inexplicably prevented from interrupting, is the proof of the musical number being over, and soon there's nothing stopping Megatron from turning to roar in indignation at this disruption of his grand plan – but he's a good few seconds too late.