Summer is here, finally — and you already know what that means: it's time yet again to hem and haw over which one track served up by our favorite pop star(s) will ultimately soundtrack our Mai Tai sipping poolside and define the year's sunny season.

Last year, PopCrush readers crowned Britney Spears and Iggy Azalea's "Pretty Girls" as our official Song of Summer 2015. But who will reign supreme in 2016?

We're kicking off this year's competition with two surefire smashes crafted by three of today's most reliable superstars: Calvin Harris and Rihanna's euphoric club cut "This Is What You Came For" and Justin Timberlake's delightfully chipper Trolls anthem, "Can't Stop The Feeling!" — both of which perfectly fit the Song Of Summer bill.

Rihanna and Calvin's latest club collabo already stormed the charts since its release, becoming Bad Gal RiRi's 28th Top 10 Billboard Hot 100 hit (and Calvin's fourth!) while topping the charts in several countries worldwide. That said, JT made even stronger showing in the sales department upon the debut of "Can't Stop The Feeling!", shooting straight to No. 1 on the Billboard Hot 100 in its first week, giving the FutureSex/LoveSounds singer his fifth No. 1 US hit.

Of course, both of these songs will no doubt remain on heavy rotation throughout the next few months. But will one of them ultimately become the defining sound of Summer '16? Place your vote below, and keep watching this week as we unveil the other tracks vying for SOS 2016 status.

This poll ends on Monday, June 27. Start voting!

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