Complex sentence: After leaving the E Street Band in 1984, Van Zandt used his celebrity as a musician to fight issues surrounding apartheid in South Africa by creating a group called the Artists United Against Apartheid.
Split into simpler sentences: After leaving the E Street Band in 1984, Van Zandt used his effect as a musician to pursue being a human rights activist. He fought issues surrounding the apartheid that had been taking place in South Africa by creating a group called the Artists United Against Apartheid.