니까

Because, since - tacked on after

Gives the reason for what was just said, and in these lines it usually lands at the end, after the point: first place, because I'm first place; this isn't the case for all artists; so we didn't have to say thank you for them. The related 을 테니까 means 'since I will' or 'since it must be' — one line promises punishment is coming, so. Compare 아서/어서, which also gives reasons but cannot be followed by a command or a suggestion, while 니까 can.