With the technology that exists today, some of the worst singers can sound like professional recording artists with a little editing in the studio.
But when it comes to singing live, even some of the most talented singers have been caught in the act of lip-synching.
“Lip-synching has been associated with something that is typically an egregious offense for a live performer,” arts and entertainment journalist Chuck Taylor told ABC News’ “20/20.” “Understanding whether a performance is live or not is … kind of a delicate thing.”
One of the times that artists may appear to not be performing live is when they use a performance track, which includes the instruments, backing vocals and hook vocals pre-recorded and playing in the background during a live show.
"So, when they go to perform it, they have the support of the stacks they recorded. They have the effects on the background vocals," Grammy-nominated recording and mix engineer Ariel Chobaz told ABC News' "20/20." "They're singing it on top. It's kind of like karaoke, in a way."
People may think artists are lip-synching because they might see a section in the performance where the artist doesn't sing and hear all the vocals from the performance track.
"But those are what we consider background vocals that were left in on purpose," said Chobaz.
Chobaz, who has worked with Nicki Minaj and Rihanna, said singing completely live can sometimes be impossible, especially during live television events.
"I've been involved in some very big broadcast shows, like the Grammys and the American Music Awards, and the time schedule is so precise. It's physically not possible to mic an entire band for every segment that comes up," said Chobaz.
During such performances, the singer's microphone is still on. On the parts they're not confident on or if the performance is physically demanding, the artist will sing quieter, and more of the performance track vocals can be heard.
“I think there are times when artists are allowed a pass, because shows have become so gargantuan, in terms of production, and dancing, and spinning around on a trapeze,” Taylor said.
There are very few artists who actually don't sing and completely lip-sync to a performance track that includes full lead vocals, according to Chobaz.
In these instances, there may be outside issues beyond just being a bad singer, such as weather conditions, technical issues, or sickness.
"At the end of the day, when it's a big broadcast event, there's very little room for error, and sometimes the show has to go on," Chobaz said. "And even if a singer is sick, that might mean relying on the pre-recorded track."
But even with technology and live-singing aids, Chobaz said, he can't fabricate the special quality that makes people stars.
"So, if someone doesn't have that texture, that feeling, that emotion, no matter how much we tune it, it won't sound good. It'll sound terrible," Chobaz said.
"You have to have a certain quality of magic to really make it work."