One player begins as “it”.
Each player joins the group forming a chorus of cycling sound, each playing a repeating pattern or simple groove. If you like you may establish this by laying Hey, adding players in one by one around a circle, each player introducing a pattern that complements the ones already being played.
The player chosen as “it”, eventually chooses a partner (perhaps secretly) and they begin to play a duet.
When the other members of the group realize that a duet is happening, they become silent and listen.
The player who is “it” and his or her chosen duet partner play together.
The rest of the ensemble listens until it truly, truly hears that it is time to rejoin the duet players.
Now that everyone is playing together, the player who was last chosen as a duet partner becomes the new “it” and the game begins again.
With practice an ensemble can learn to play this game without anyone ever being explicitly designated as “it.” The duets form organically.