In the early days of rap and hip-hop stylistic fusion was essential to the artistic creativity of DJs, MCs, B-boys, and grafitti artists. One style that was intwined with hip-hop was electro. Electro is a dance-based experimental electronic music that combines various elements from disco and funk to German and Japanese techno. It was most popular during the mid '80s, coincinding with the blossoming of early hip-hop. Electro is important to hip-hop because it was initially designed as breakdance music. DJs developed electro, which had distinctive drum patterns and manual looping. It did not stand on its own as a style for long but was quickly enveloped into various different styles (rap, techno, freestyle, industrial).
Influential artists/DJs to electro were:
For further information on Electro (including a great diagram which illustrates what different styles influenced and were influenced by Electro) see the All Music Guide to Hip-Hop.