question: The Sword , High on Fire , Witchcraft and Wolfmother are all examples of what hard rock sub-genre ?
answer: retro-metal
turker_answer: The Sword , High On Fire , Witchcraft and Wolfmother are all examples of the retro-metal hard rock sub-genre .
rule-based: The Sword , High on Fire , Witchcraft and Wolfmother are all examples of retro-metal hard rock sub-genre .