Answer:
In 1979, Sugarhill Gang a notorious rap group that was produced by Sylvia Robinson released a Hip-Hop track called "Rappers Delight".
Besides appealing to a wider audience the single track recorded over 2 million copies in sales within the United States which earned Sugar Hill Records approximately US$3.5 million.
This realization of how much money could be made from rap became the tipping point for rap which moved from being street music to a commercial commodity.
Since then, rap has become sophisticatedly commercial with lots of rappers who have gone on to sell millions of albums in a week. Eminem is currently the highest-selling solo rapper of all time.
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