Complex sentence: Gumboot dancing was conceived by black miners in South Africa as an alternative to drumming--which authorities restricted one of the other reason for gumboot dancing was for the miners in South Africa as they worked they sang.
Split into simpler sentences: Gumboot dancing was conceived by black miners in South Africa as an alternative to drumming--which authorities restricted. Another reason for gumboot dancing was for the miners in South Africa as they worked they sang.