To base your ideas on. I always say, you have to acknowledge who came before you. How many "rappers" do you know that listen to the shit that's out now, and they base their foundation on that, (with no knowledge of your Rakims and Melle Mels and Kanes and sadly even G Rap) and they're horrible amateur hacks. If you are ignorant of the standards in your craft, you will end up doing some shit that's already been done, years before and much better. I notice people who I know for a fact dont study hip hop, but they say they make "hip hop" it's like their idea of it is really weak, basically they do some weak ass shit and think it's tight. U gotta know your sport.