James Taylor's commercial breakthrough in 1970 was predicated on the relationship between the private concerns expressed in his songs and the larger philosophical mood of his audience.
He was going through depression, heartbreak, and addiction; they were recovering from the political and cultural storms of the '60s.
On his follow-up to the landmark Sweet Baby James, Taylor brought his listeners up to date, wisely trying to step beyond the cultural, if not the personal, markers he had established.
Despite affirming romance in songs like "Love Has Brought Me Around" and the moving "You Can Close Your Eyes" as well as companionship in "You've Got a Friend," the record still came as a defense against the world, not an embrace of it; Taylor was unable to forget the past or trust the present.
The songs were full of references to the road and the highway, and he was uncomfortable with his new role as spokesman.
The confessional songwriter was now, necessarily, writing about what it was like to be a confessional songwriter: Mud Slide Slim and the Blue Horizon served the valuable function of beginning to move James Taylor away from the genre he had defined, which ultimately would give him a more long-lasting appeal.