What is an ‘MC’?
One hears it used to refer to many black entertainers, but what does it stand for?
Used to mean Master of Ceremonies.
I'll try to explain it as untediously as possible, but the explanation will still be tedious.
In the pre-hiphop world of the 70s to "rap" was to smooth-talk. If someone was good at talking his why into ladies' bedrooms, or at selling stuff, or at explaining his way out of trouble he had "a good rap."
Isaac Hayes had a series of songs in the late 60s/early 70s called Ike's Rap I", "Ike's Rap II" etc. all featuring Hayes' spoken word seductions over a funky instrumental.
In the mid- to late-70s, breakbeat DJs started the very first hip-hop musical events. They employed MCs (masters of ceremony) to be their hosts. These MCs would exhort people to dance, comment on the dancing prowess of attendees, compliment attractive women in the audience, make announcements, hawk new recordings, advertise upcoming breakbeat dances, etc. - increasingly in rhyme as time went on.
Many of these MCs were called "rappers" because of their glibness and smooth-talking.
The first-ever hiphop record to chart was called "Rapper's Delight", and since then most casual fans of hiphop have called hiphop "rap" and the MCs who rhyme over the beats as "rappers", but on the East Coast - especially in NYC, the artist who speaks the lyrics is normally called an MC.