Conversation so far:
What is the interregnum?
An interregnum is a period of discontinuity or gap in a government, organization, or social order.
What is In The Wake of Poseidon?
In the Wake of Poseidon is the second studio album by English progressive rock group King Crimson
Was the album In The Wake of Poseidon by King Crimson a success?
US Billboard 200 31
Was Lizard another album?
Lizard is the third studio album by British progressive rock band King Crimson
Was Lizard successful?
In 2011, PopMatters named the title track at #13 in the list The 25 Best Progressive Rock Songs of All Time.“

Question: What genre is the band's music?
Self-contained rewrite: What genre is King Crimson's music?