Selena Gomez cries during concert: Star who's had the biggest onstage breakdown?

Why so sad, Selena? 

Selena Gomez got pretty emotional during her concert in Brooklyn on Wednesday, and shed more than a few tears while singing her ballad "Love Will Remember," which is rumored to be about ex-boyfriend Justin Bieber.

SODAHEAD SLIDESHOW: Biggest onstage meltdowns

The 21-year-old singer has mentioned before how personal that song is to her. Earlier this year, she told InStyle magazine: "Obviously, 'Love Will Remember' is a personal song to me and I don't really need to say anything," she told the mag. "I think my fans will get it. I think people will figure it out themselves ... I'm sure he'll like it too."

Gomez was teary throughout the entire song, but she had a particularly tough time getting through the lyrics, "We used to be inseparable, I used to think that I was irreplaceable."

Breakups sure are tough, but did Selena have one of the biggest breakdowns on stage? How about last year when Billie Joe Armstrong freaked out at the iHeartRadio music festival because he only had one minute left to play? Or the time Kanye West broke down onstage while singing "Hey Mama," a song about his late mother?

There are tons of musical meltdowns worth noting. But which star's had the biggest onstage breakdown to date?