Let's start from a shared agreement that the Chicken Dance, Hokey Pokey and YMCA are not for everyone. Most clients agree that they don't want "cheesy" music played at their event. I have always interpreted this to mean that the music and the presentation of the music should not seem forced or cliched. You want your event to be reflective of you and your guests. Where it becomes challenging for a DJ is coming to a clear and consistent expectation of where to draw the line in the Velveeta. One person's "We Are Family" is another person's "Margaritaville."
DJs should work with you to get a solid understanding of which songs are OK, which songs are maybes if requested and which are grounds for dismissal. You will be well served by giving your DJ Today, DJs can and should be able to draw from the world's catalog of music. The cloud provides us with ready access to nearly every song ever recorded.
With apologies to Meghan Trainor, the quality of sound at an event is dependent upon many factors including bass, treble and mid-range sound as well as the placement of the speakers and the natural acoustics the venue provides. Any good DJ should arrive well before the guests, and have a clear understanding of the sound requirements for your room or outdoor area. In recent years, I have switched to the BOSE L1 Model II PA systems. For weddings, I bring two of the systems and run them through a Numark Mixer. What this means for you, is that 48 individual speakers in four speaker arrays and two powerful sub-woofers will deliver 365 degrees of sound that will be as clear at the back of the room as it is at the DJ table.