The tree peepers have already been in song, ever since the days and evenings first got warm. Some friends have an on-going discussion if they're frogs or bugs, then another friend called them peepers, and of course that's what they are. I refuse to Google it! (I did Google the "periodical cicadas".)
For me, it's the chorus of the world around us. In the foothills of the Himalayas in the early summer, the cicadas sing in the treetops in anticipation of monsoon's imminent arrival. The volume crescendos till the first drops of rain, then they are quiet until next summer.
We all have parts in the song. We people just sing along the harmony. Together we make a beautiful symphony.