Over the course of its two weekends, there are nearly 300 artists performing at Ultra Music Festival this year. In 2013, the festival is celebrating its 15th anniversary as dance music's most celebrated occasion and the season's highly anticipated kick off. In that period of time, the lineup has changed a lot -- not just in scope but also in sound -- but there are names that remain pillars of Miami's greatest electronic music tradition. These are names who've been at it longer than many of us have been walking and they deserve not just a tip of the hat, but also your time and attention at their impending Ultra sets. How will we know where we're going if we don't know where we've been?