MC

MC can mean a lot of things. It’s most commonly used in old school Hip-Hop where it means Microphone Controller or Move the Crowd

Yo man these rappers today ain’t comparable to the MC’s

Man them MC’s back in the days was fire

Sound

Sound is like saying “ok, deal, yep, alright, cool” etc. It means that you’ve understood what a person just told you

Friend: Bro make sure to call me back Friday
Me: Sound

Coach: Make sure to mark your man
Player: Alright sound boss