Slacker's end-of-year countdowns are a true representation of the music that you cared about most this year, as determined by the songs that you listened to, "hearted," and shared the most. We call it EQ, which stands for "Engagement Quotient." From Ariana Grande to Zedd, with stops at Iggy Azalea, Sam Smith, Nico & Vinz, and Florida Georgia Line, Slacker host Parker has your favorite songs from the last 12 months.