The most important thing to remember about having a career in the music industry is to always stay ahead - there is nothing worse than not knowing what to do next or how to handle a sitiation. In this business you always need to be prepared. For example, this upcoming Saturday is my very first Mitzvah as the DJ. In order to prepare for this I am meeting with the MC of the party, going over the timeline and planning out what we want to do. That way there will be no surprises when Saturday comes.
Now not every party or event will run as expected, whether the adults don't want to dance or the catering company doesnt follow the timeline, something usually always happens. As the entertainer it is your job to not only provide the entertainment but also troubleshoot and quickly fix any problems that may occur with your equipment or staff. The customer didn't pay you to sit back and relax, they expect you to be on your feet, provide your all and make the party.
Get ahead and show your skills, you'll eventually land that major gig because of your hard work.