When you’re MCing for breakers, it’s important to know the moves and pay attention to the dancers. When your rapping, you cannot start slipping because the breaker might slip as well and break their bones. The MC in this case is not only the master of cermony, but also a mic controller and has power over the dancers with his voice. You watch the dancers and try to figure out what they are up to. You might, for example, recognized that one of your bboys is prepering to do a monkey. Then you would get ready to rhyme about the monkey and it would happen at the same time.
from Martha Coopers Hip-Hop Files 79-84