Buzz can build and die quickly on the internet, but things move slower on terrestrial radio, or your cousin's Spotify. The songs that will be everywhere in June and July may not yet be apparent, but they have probably already been released. With that in mind, here are some early contenders for 2015's Song of Summer. It's possible there's a clear winner that's yet to emerge—Rihanna, what is your next single?!—but for now, this is the weird field.
Evidence of heat: 12 weeks on Billboard's Hot 100 chart, 40 million Spotify streams
Last year's version: Iggy Azalea f. Charli XCX, "Fancy"
Evidence of heat: 145 million Spotify streams, Another 43 million vide views
Last Year's Version: Jason Derulo, "Wiggle"