UPDATE: Lady Gaga's 'Bad Romance' won in Round 1! Vote for 'Bad Romance' in Round 2 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!

Two powerhouse pop divas are facing off against each other in one tough competition! Christina Aguilera and Lady Gaga both have a reputation for incredible vocal talent and pushing the limits. They are two of the biggest pop stars of all time, and they have a library of huge hits to back it up. Which song is more deserving of the Greatest Pop Song of the Modern Era title: Christina's 'Beautiful' or Lady Gaga's 'Bad Romance'?

Christina proved that while she can own a dance hit, she can also bring it with a power ballad. 'Beautiful,' released in 2002, was just the track to do that. The stripped down track highlights Christina's insane vocal range while also revealing her vulnerable side. The empowering song won a Grammy and is still considered one of her greatest.

Gaga continued her takeover of the pop music world with 'Bad Romance' in 2009. The uptempo track captivated listeners with its catchy beat and anthemic chorus. 'Bad Romance' won two Grammys and proved that once again, Mother Monster was changing the face of pop music.

Is 'Beautiful' or 'Bad Romance' more iconic? You can vote once an hour until the polls close on March 11 at 12PM ET. The song that wins in this round will move forward to the next round of our Greatest Pop Song of the Modern Era tournament.