My wife and I recently got married in April on the beach in Tulum.  Our wedding planner recommended DJ Luca, and we couldn't have been happier.  He communicated with us beforehand to get songs we wanted to hear during the ceremony, cocktail reception, dinner and dancing.  He found all of the songs that we wanted, including some pretty obscure Russian ones for my wife's family!  He was professional every step of the way, and helped arrange so that our friends could play guitar and sing a song through his amp and equipment during the ceremony.  He can either stick to your playlists or play songs according to your genre tastes and crowd (or any combination thereof).  We let people request songs at the end of the dancing party, and he was more than happy to oblige.  He also has good equipment and speakers (which is important).  More importantly he has a great attitude and a pleasure to work with, we were glad we chose him.