Did Selena Gomez have a small meltdown at Jingle Ball 2013 in Los Angeles last night (Dec. 6)?

Witnesses at the concert described it as such when the Disney alum had sound issues onstage and then launched into a tirade of self-deprecating putdowns and backhanded messages to the audience. What happened?

Gomez, sporting a black and red lacy bodysuit, a short bob wig and black lipstick, opened with 'Birthday' and then launched into her second song, 'Undercover.' Afterward, she finally greeted the roaring crowd ... but there was an issue.

In the video above, it's hard to tell exactly to what she was referring, but because the tracks she performed were so close to her album cuts as to be nearly identical in sound, a possible lip sync fiasco could have been at play, or perhaps Gomez's monitors were just out of sync.

"Sorry, the sound isn't working!" Gomez yelled sheepishly. "Are you guys having a good night?" She continued, "I promise, a lot cooler people are gonna come out tonight. Is it OK if I perform two more songs and you guys can get to it?"

Except she didn't immediately start performing again. "Thank you ... I have to thank you guys so much for allowing me to be able to perform the music that I love. And I have to say that before you guys go on to the people that you care about, I really appreciate you supporting everything that I do. So this next song is the first song I had hit No. 1, and it's called 'Come & Get It.'"

She performed the song seemingly without a hitch ... and that was it. There was no second song following it, no goodbye to the crowd, nada. What happened? Watch her full set above (start at 07:50) and decide for yourself, PopCrushers.

UPDATE: Gomez was, in fact, caught lip syncing. See more videos below -- including one in which Gomez drops an F-bomb!

Watch Selena Gomez Struggle Through 'Come & Get It'

Watch Selena Gomez Drop an F-Bomb (Language NSFW)