Sentence:  Parties were splitting, forming, merging, and dissolving in such rapid succession that the game of <WSD>musical</WSD> chairs seemed to describe what was going on better than any known theory of political science. 
Meaning of the word marked with <WSD> tags:  Pertaining to a class of games in which players move while music plays, but have to take a fixed position when it stops; by extension, any situation where people repeatedly change positions.