Breaks and Stops are very important in traditional jazz. You ZAP the first note of the break. If played with authority, they really zip up the tune and make it more fun to play. A nifty break by a newcomer is most impressive. They may be testing you.
Dynamics is very important.
Volume well might vary from strain to strain or chorus to chorus. Or vice versa. A great effect is to drop the volume of bars 17-23 in the out chorus, then really hit the last 8 bars. Some consistently play a hot out chorus. 1920s pop tunes .