Final answer:
The first big hip-hop record in 1979 was 'Rapper's Delight' by The Sugarhill Gang, which played a pivotal role in bringing hip-hop to a wider audience and marking the expansion of the genre beyond its New York City roots.
Step-by-step explanation:
The first big hip-hop record released in 1979 was 'Rapper's Delight' by The Sugarhill Gang. This single is often credited with bringing hip-hop music to a wide audience, marking a significant moment in music history. Although hip-hop music had been developing for several years with artists like the Last Poets and Gil Scott Heron, 'Rapper's Delight' was the track that brought the genre into the mainstream, reflecting the experience of inner-city life and navigating through various socio-cultural issues.
Following the contagious diffusion pattern, hip-hop spread from New York City and Northern New Jersey to more distant cities over the decade, with groups like DJ Jazzy Jeff and the Fresh Prince making it to the record charts by 1988. It wasn't until 1989 that hip-hop acts from Los Angeles also began achieving mainstream success. The dissemination of hip-hop followed the model of contagious diffusion, demonstrating how cultural movements expand and influence beyond their initial localities.