UPDATE: The Backstreet Boys' 'I Want It That Way' won in Round 1! Vote for 'I Want It That Way' 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!

New Kids on the Block and the Backstreet Boys are two of the biggest boy bands of all time, and the songs highlighted here as part of March Music Madness are arguably their most successful. 'Step by Step' hit a chord with early '90s pop fans, while 'I Want It That Way' made its mark in the late '90s. Will it be 'Step by Step' that moves on to the next round in our Greatest Pop Song of the Modern era bracket, or will it be 'I Want It That Way'?

'Step by Step,' the infectious title track from an album with the same name, is NKOTB's top-selling single and spent three weeks at No. 1 in the U.S. in 1990. The lyric "Step one: We can have lots of fun" rang true with this catchy pop tune, and the song -- with its sweet message about falling for a girl -- made the group (Jordan Knight, Danny Wood, Donnie Wahlberg, Joey McIntyre and Jonathan Knight) even more popular than they already were at the time.

'I Want It That Way' was released nine years later (in 1999). At the time of its release, fans were already smitten with the stars of the group, A.J. McLean, Howie Dorough, Nick Carter, Kevin Richardson and Brian Littrell, thanks to past singles like 'Quit Playing Games (With My Heart)' and 'As Long as You Love Me.' But it's the ballad 'I Want It That Way' that became one of the boys' most well-known songs. While it surprisingly only reached No. 6 on the U.S. charts, it peaked at No. 1 in over 25 countries and was nominated for three Grammys. And while we're still not sure what the phrase "I want it that way" really means in the context of the rest of the song's lyrics, 'I Want It That Way' never fails to get stuck in our heads at the mere mention of its title -- and that's not a complaint.

The two groups joined forces as NKOTBSB in 2011 for an album and tour (our minds were blown by this!), but which song is more worthy of becoming the Greatest Pop Song of the Modern Era? Vote for 'Step by Step' or 'I Want It That Way' here -- you can vote up to once an hour. The song with the highest percentage of votes will move on to the next round, so keep on voting until this poll closes at 12PM ET on March 11.