What's really the difference between mainstream and underground rap?

yeah you pretty much got it right mainstream rap is all the rap you hear on the radio, and the songs the rappers put on their albums. Examples of this would be:
Lil Wayne: Got Money, A Milli, (you know the radio stuff)
And underground is the stuff that you never hear unless you go searching for it like some rappers release mix tapes and some of their underground songs will probably will be on there. But yeah some mainstream rap is good but most of the underground stuff is better

Underground = good
Mainstream = bad

ya you pretty much got it, Underground=good, Mainstream=bad, guys go underground so money hungry people in the rap game dont tell them what to do and what music to make, cause in mainstream all that matters nowadays is money

Mainstream rap is what you listen to. (your not street)
Underground rap is what lyricist and "Hip Hop Connoisseurs" such as myself listen too.

How can I make this assumption? Because if you have to ask that question, it's obvious you'll never be able to be figure it out.

Line from an underground rapper, "Slug" of the group "Atmosphere", "I got some last words, **** ALL OF YAW! Stop writing raps, and go play volleyball."

Honestly, Underground has just as much shyt as Mainstream.

A mainstream artist is one who has a large fan base. An artist you'll find on MTV and BET, as well as the radio.

An underground artist is one who's fan base is significantly smaller than those in the mainstream. You'll very rarely find an underground artist's music on radio stations and TV.

I will say that underground artists usually have almost complete creative license over their music. Mainstream artists have people to answer to i.e. record labels, managers, producers, etc. Simply because of that the lyrical quality is sometimes better in underground music than mainstream. And vise versa the production is sometimes worse. However, there are good and bad artist in each so you shouldn't discredit an artist simply because they're mainstream or underground.

I was wondering much the same thing

1

It's also based on your dependency on your label. Mainstream artists typically rely on their label to handle financial assets like drugs, cars, clothes, women, song writers, etc. But they always have to pay it back, which is why there are artists that have had to file bankruptcy. So all that "I got money *****" nonsense is preposterous.

The artists notoriety, amount of record sales, and the amount of advertising and media coverage about the artist.