Circus marches bring audiences to the front of their chairs. You can almost see the lions, trapeze artists, and equestrians; and you can almost smell the popcorn and exotic animals when you listen to a circus march.
Circus marches are ideal in certain spots in informal indoor or outdoor concerts:
At the beginning of a concert, immediately after the Star Spangled Banner.
Immediately prior to a concert intermission.
Immediately following a concert intermission.
At the end of a concert.
In an informal concert setting a circus march is a well understood cue to an audience that is enjoying its intermission that it is time to sit down for the second half.