"C'mon" is a casual contraction of "come on" used to urge someone to act or move. It can show impatience, disbelief, or friendly encouragement. Tone depends on context and delivery.
C'mon, baby, c'mon darling, Let me steal this moment from you now. C'mon, angel, c'mon, c'mon, darling, Let's exchange the experience, oh... Kate Bush
C'mon everybody, yeah, this is your life I'm talking about a revolution we gotta organize We don't need no segregation, we don't need no race New age revelation, I think we got a case.I'm OK as long as u are here with me Sexuality is all we ever need. Prince (musician)
You see people who are 19 or 20 years old and they don't even know who The Who is. It's like, where have you been? Justin Timberlake? C'mon. Where are the roots? Dustin Diamond
Don't you know that I'm not joking? Aah, you think you won't, I think you will. Don't you know that this tongue can kill? C'mon, c'mon, c'mon, c'mon, c'mon, c'mon. Lady kiss that frog. Peter Gabriel
My hotel doesn't have a 13th Floor because of superstition, but c'mon man... People on the 14th Floor, you know what floor you're really on. "What room are you in?" "1401". "No, you're not. Jump out of window, you'll die earlier!". Mitch Hedberg
David Lee Roth had the idea that if you covered a successful song, you were half way home. C'mon - Van Halen doing 'Dancing in the Streets'? It was stupid. I started feeling like I would rather bomb playing my own songs than be successful playing someone else's music. Eddie Van Halen