A concert or other live performance where the performer is not actually performing (lip synching) or is only hologram.
Breht: When I was in Japan, I went to the Hatsune Miku Live concert. You know where the performer is actually a hologram.
Griffin: You mean you saw in her noncert. If the performer is not real it is not a concert.
Tabitha: I saw the Britney Spears Concert and she was lip synching. What a noncert.