By the 1980s, hip-hop music (the combination of the elements of DJ-ing and MC-ing) pushed itself to the forefront of the culture as its most popular expression, and also the most profitable. Major record labels began signing numerous hip-hop acts and profited immensely off their success.
The most popular of the early-to-mid 80s hip-hop groups was Run-D.M.C., who helped to build the legendary music label Def Jam Records, run by hip-hopper Russell Simmons. They were pioneers, and one of the most important and legendary groups in the history of hip-hop. Run-D.M.C. was the first hip-hop group to have a number one album on the R&B chart; to have a top-ten album on the pop chart; to have certified gold, platinum, and multi-platinum albums; to appear on the cover of Rolling Stone; to receive a Grammy Award nomination; to have a video on MTV; and to receive an athletic product endorsement deal (Adidas). Therefore, Run-D.M.C. did more than anyone in history to take hip-hop into the mainstream. During this era, hip-hop was still centered in New York City, with all of its artists originating from one of the five boroughs (The Bronx, Brooklyn, Manhattan, Queens, and Staten Island). But that began to change by the mid-to-late 80s as hip-hop groups began cropping up in various cities across America like Philadelphia, Miami, Houston, and Los Angeles.