The "Spinning Wheel" is an intriguing metaphor for the cycles of events we go through in life. There is also carousel imagery in the song, as David Clayton-Thomas references the carousel horses in the line, "Ride the painted pony."
This was inspired by a Joni Mitchell song called "The Circle Game
," where Mitchell sings about seasonal cycles and brings in the carousel with the line, "The painted ponies go up and down."
This marked the first instance of a Joni Mitchell influence in a popular song. Like Clayton-Thomas, Mitchell is from Canada, and he heard her work long before most. Mitchell didn't release her first album until 1968, but in the years prior she developed a reputation as an insightful songwriter and performer, and Clayton-Thomas was a big fan. Mitchell didn't release her version of "The Circle Game" until 1970, but Buffy Sainte-Marie recorded it in 1967 and Tom Rush in 1968.