The phrase "musical chairs" refers to a game played by children, where they sit in a circle and one chair is removed while music plays. The players then walk around the circle, and when the music stops, each player tries to grab a seat. Whoever doesn't get a chair is out of the game until there are only two or three people left standing. The phrase can also be used metaphorically to describe situations where resources or opportunities are limited, and people must compete for them.