UPDATE: Britney Spears' 'Baby One More Time' won in Round 3 and has moved on to the Semi-Finals. Vote for the song 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!

Round 2 of voting for the Greatest Pop Song of the Modern brought us two of the toughest battles we've seen thus far in this year's March Music Madness tournament. The Backstreet Boys brought in 51.49% of the votes with their catchy hit 'I Want It That Way' and wound up winning against Whitney Houston's classic 'I Will Always Love You.' Meanwhile, Britney Spears and Hanson fans dueled up until the very last second, but in the end, 'Baby One More Time' topped 'MMMBop' with 53.12% of the votes -- and now the song is moving on to Round 3 to face 'I Want It That Way.' Will 'I Want It That Way' or 'Baby One More Time' be the song that gets one step closer to being titled the Greatest Pop Song of the Modern Era?

'I Want It That Way' first made its way into the hearts of pop music fans around the world back in 1999, and its impressive feats include hitting No. 1 on the charts in more than two dozen countries and getting nominated for three Grammys. The track is still known as one of BSB's signature songs, and if you played it right now, it's pretty much guaranteed that you'll be singing along with A.J., Howie, Nick, Kevin and Brian in no time.

'Baby One More Time' was released in 1998, just a year before 'IWITW.' The success of the song -- which went No. 1 around the world and earned a Grammy nomination -- launched a massive career in pop music for Britney Spears. To this day, the song and its video remain iconic pop culture mainstays.

For true '90s pop fans, making a decision about who to pick in this round of voting will likely be insanely difficult. But only one song can move on to the next round! Keep in mind that you are welcome to vote up to once per hour until the polls in Round 3 close at 12PM ET on March 25. Ultimately, either 'I Want It That Way' or 'Baby One More Time' will move on to become one of the final four songs in the Greatest Pop Song of the Modern Era competition.