The 'Begin Again' actress, who plays aspiring singer Greta in the upcoming comedy-drama, took vocal lessons for the movie and said she will not be seen singing in a bar, reported Contactmusic.
"I hate karaoke. It's my idea of hell," she said.
Knightley, 29, had earlier said that she wanted to sound like Adele in the film.
"I had actually done it on one other movie but in a very different style, but no, I've never sung like this. I was actually quite disappointed that I didn't sound like Adele.You know when you're in the shower and you're just singing and you think, 'Wow, I sound really good right now'," she had said.