August 11, 1973 is widely celebrated as Hip-Hop's birthday. It's the day that Clive "DJ Kool Herc" Campbell and his sister Cindy Campbell, threw a "Back To School" jam at the address of 1520 Sedgwick Avenue in the Bronx. It was at this party that Herc debuted a new technique of extended the break of popular records by mixing two records of the same song together. It was an innocent spark that spread like revolutionary wildfire.

Hip-Hop's true first wave wasn't made up of recording artists. These were creatives coming together in a community across the South Bronx and eventually other parts of New York City. But by the end of the 1970s, DJs and graffiti artists and breakers had provided a foundation on which emcees could launch viable careers, and rap records became a reality. Labels like Sugar Hill and Enjoy Records scooped up acts from across Uptown and the Bronx, as groups like Grandmaster Flash & The Furious Five, The Treacherous Three, and the Funky Four Plus One suddenly made the leap from the parks to the recording booths.

By the mid-1980s, artists like Run-D.M.C. and Whodini, along with the emergence of the Def Jam label, spelled the beginning of the end for rap's first wave. But there is some tremendous music that came out of Hip-Hop's first generation, songs that became calling cards for the genre for decades to come. We picked 25 of the songs that helped shape, define, and ultimately bookend, Hip-Hop's "True School" wave up through 1984 (and some 1985.)