Question: What is a compilation album of previously unreleased songs and alternate takes recorded 1969–1980 by American singer-songwriter, who was one of the most popular acoustic artists of the decade and one of its best-selling artists?
Sentence (from "Forever, John"): Forever, John is a compilation album of previously unreleased songs and alternate takes recorded 1969–1980 by American singer-songwriter John Denver.
Relevant evidence: Yes