Complex sentence: Mtume (pronounced "em-tu-may") was a funk and soul group that had several R&B hits, which led them to become one of the more successful producers and performers of R&B and funk music in the early 80's.
Split into simpler sentences: Mtume (pronounced "em-tu-may") was a funk and soul group that had several R&B hits in the early 1980s. The group became one of the more successful producers of R&B and funk music in the early 80's.