a slight little story of 1970-1980-1990-2000

1970-Hip hop arose during the 1970s when block parties became increasingly popular in New York City, particularly in the Bronx, where African American and Puerto Rican influences combined.Block parties incorporated DJs who played popular genres of music, especially funk and soul music. Due to the positive reception, DJs began isolating the percussion breaks of popular songs. This technique was then common in Jamaican dub music and had spread to New York City via the substantial Jamaican immigrant community.
1980-The 1980s marked the diversification of hip hop as the genre developed more complex styles Early examples of the diversification process can be identified through such tracks as Grandmaster Flash's "The Adventures of Grandmaster Flash on the Wheels of Steel" a single consisting entirely of sampled tracks.
as well as Afrika Bambaataa's "Planet Rock" (1982), which signified the fusion of hip hop music with electro, In addition, Rammellzee & K-Rob's "Beat Bop" (1983) was a 'slow jam' which had a dub influence with its use of reverb and echo as texture and playful sound effects. The mid-1980s was marked by the influence of rock music, with the release of such albums as King of Rock and Licensed to Ill.
1990-In 1990, MC Hammer hit mainstream success with the multi platinum album Please Hammer, Don't Hurt 'Em. The record reached #1 and the first single, "Can't Touch This" charted on the top ten of the billboard hot 100. MC Hammer became one of the most successful rappers of the early nineties and one of the first household names in the genre. The album raised rap music to a new level of popularity. It was the first hip-hop album certified diamond by the RIAA for sales of over ten million. It remains one of the genre's all-time best-selling albums. To date, the album has sold as many as 18 million units.
2000-The popularity of hip hop music continued through the 2000s. In the year 2000, The Marshall Mathers LP by Eminem sold over ten million copies in the United States and was the fastest selling album of all time. Nelly's debut LP, Country Grammar, sold over nine million copies. In the 2000s, crunk music, a derivative of Southern hip hop, gained considerable popularity via the likes of Lil Jon and the Ying Yang Twins.
Hip hop influences also found their way increasingly into mainstream pop during this period mainly the mid 2000s. In the East Coast, popular acts during this period included 50 Cent, whose 2003 album Get Rich or Die Tryin' debuted at number one on the U.S. Billboard 200 charts.
In addition to the mainstream success, the United States also saw the success of alternative hip hop in the form of performers such as The Roots, Dilated Peoples, Gnarls Barkley and Mos Def, who achieved significant recognition. Gnarls Barkley's album St. Elsewhere, which contained a fusion of funk, neo soul and hip hop, debuted at number 20 on the Billboard 200 charts. In addition, Aesop Rock's 2007 album None Shall Pass was well received, and reached #50 on the Billboard charts.