UPDATE: Katy Perry's 'Firework' won in Round 2! Vote for ‘Firework’ in Round 3 of the competition here.

Welcome to March Music Madness! Here at PopCrush, we’ve selected 32 of the most iconic pop songs released from the ’80s to today (divided into brackets by decade) — and now it’s your job to vote and decide which song will be named the Greatest Pop Song of the Modern Era. May the best song win! 

Katy Perry and Carly Rae Jepsen are going head to head in Round 2 of March Music Madness! During Round 1, Perry's anthemic 'Firework' beat out Miley Cyrus' 'Wrecking Ball' with 61% of the votes. It was a closer call for Carly Rae Jepsen's 'Call Me Maybe,' which just barely won over One Direction's 'What Makes You Beautiful' -- but ultimately Jepsen edged 1D out of the competition with slightly more than 55% percent of the votes. Now, 'Firework' and 'Call Me Maybe' are battling it out! Which pop song could be the Greatest Pop Song of the Modern Era?

Katy Perry's 'Firework' is one of the singer's most iconic songs -- and for good reason! The hit, which landed the No. 1 spot on the Billboard charts and was nominated for two Grammy Awards, is a power anthem with inspirational lyrics and hard-hitting vocals that just make you want to go out and show the world what you're made of. Though the song is very dance-friendly, the simple yet powerful message behind the single is what makes 'Firework' so great -- and word has it Perry believes it is the most important song off of her album 'Teenage Dream.'

Carly Rae Jepsen's 'Call Me Maybe' was the feel-good song during Summer 2012, and the infectious, catchy hit made her world-famous. Plus, you know the song has to be good if it was powerful enough to knock One Direction out of the March Music Madness competition! Like 'Firework,' 'Call Me Maybe' scored the No. 1 spot on the charts and was also nominated for two Grammys. The upbeat tune brought back all of the best things about teen bubblegum pop and made Carly Rae Jepsen synonymous with the hit.

Whose hit is the Greatest Pop Song of the Modern Era? You can vote for 'Firework' or 'Call Me Maybe' once every hour until the polls close on March 18 at 12PM ET. The winning song will continue on to the next round of the competition!