If performance means any act, in the meaning of 'action' and not just 'to act in a perfomance', then the word performance loses the meaning of a perfomance and we would no longer be able to distinguish performances from any act and so the whole idea of being able to licence them would become rather problematic.
The legal definition of "performance" means that the song (or a portion thereof) was played in a public setting. Given the number of hits the video received, this performance was, unambiguously, public.
