/jp/ - Otaku Culture

As anon said before, the way to spot lip-sync is to watch and listen. Try to spot small sighs and trembles in their voices (it's easier if it's a solo or duet, and harder when they're singing in unison).

Watch Fall 2007 Bonkyu! concert, Koharu's Chance! (around minute 30), notice how "perfect" is the song and how did she move her mouth at the end of the song (probably to say thanks) but we hear no sound. Gentlemen, believe it or not, that is a lip-sync.
The next song is JunLin's Suki na Sempai, if you listen closely you'll notice that there are small sighs (like they are blowing into the mic) and their voices tremble a bit (specially when they move). They aren't very good singers but nevertheless that's a live performance.

My bet is that most of them lip-sync the songs with intense choreography but actually sing those with calmer steps (like those where they just stand there singing).

>If you think Ai is lip syncing, you are a major motherfucking faggot.
QFT