Denver began his recording career with a group that had started as the Chad Mitchell Trio; his distinctive voice can be heard where he sings solo on Violets of Dawn, among other songs.
Olivia Newton-John, an Australian singer whose across-the-board appeal to pop, MOR, and country audiences in the mid-1970s was similar to Denver's, lent her distinctive backup vocals to Denver's 1975 single "Fly Away"; she performed the song with Denver on his 1975 Rocky Mountain Christmas special.