You may have noticed on the dance floor that some dancers are able to perform moves which match changes in the flow of the music. These dancers haven't necessarily memorized the music -- most swing music actually has a regular and predictable structure. The chorus of most swing songs consists of 32 bars which as a whole follow an AABA structure. Each individual letter consists of four 8-count sections and the B letter has a different melody. The fourth 8-count section of each letter is often an ideal time to execute a break.
If you have swing music available, try listening to it now and see if you can notice this structure.