Is it “live” or is it “Memorex”?   Spoiler Alert:  Not all pop-stars sing live (gasp).  Some are just simply lip-syncing.  When they’re really good at it, you usually can’t tell, but when things don’t go as planned, it’s a train-wreck.

Here’s a compilation of some stars that failed badly.  (Who will ever forget Ashlee Simpson’s awful performance on Saturday Night Live?).   There’s a few new ones in the clip that I’d never seen before, including Justin Bieber blowing chunks in the middle of his recorded vocals.

Check out the fun and sometimes cringe-worthy video above.