From the smash hit (well, in my mind anyway) US television series 3-2-1 Contact! from the Children's Television Workshop and PBS. Broadcast from 1980-1992. Performed by Al Dana, Hank Martin, Tish Rabe, and Ruth Sherman.

I grew up with this show, boy does it take me back. Notice that ism's writeup under 3-2-1 Contact is incorrect, at least according to the .mp3 I just listened to (which sure sounds authentic). Notice, also, that this song conveniently explains both when and why Everything happens. Coincidence? I think not.

3-2-1-Contact!
... is the secret,
... is the moment,
when everything happens,
Contact!

...is the answer,
...is the reason,
that everything happens,
Contact!

Let's make contact!  <boing>

3-2-1-Contact!