Here’s a nice little warm-up activity, for exploring all kinds of musical elements including improvisation and dynamics.
Everyone sites in a circle. In the middle you have two instruments. They can be anything; I often use a couple of xylophones or glockenspiels, but unturned percussion works as well.
Learn the chant, tapping the pulse (syllables in capital letters.)
“WHO will be NEXT, WHO will be NEXT, WHO will be NEXT for a COFFee and a CHAT?”
Now you are ready for the game; You pass a beater round the circle in time to the pulse. Whoever has the beater on the word “CHAT” chooses a partner from the ring, and they go into the centre and have a musical conversation. Let them have a reasonable amount of time together, before calling “time”. The children return to their places and off you go again.
To begin with, the children may be a little unsure of what to do, but soon you will find (with a little encouragement and a few hints) they will start listening and responding to each other. Questions to ask are
“Do you always take turns when you are talking?” 
“Do you think they are agreeing with each other?”
“Does he sound happy or cross?”
“What do you think they were talking about?”
The children were mesmerised when I did this last week; I was surprised at how attentively they listened. We probably ran the game for about six or seven pairs before I judged it time to move on to another activity.
