What's Going On is both time-stamped and timeless: a picture of Vietnam-era turmoil that will blow minds as long as there are ears. This 40th-anniversary version lives up to its bombastic billing: two CDs and a vinyl LP, plus demos, B sides and the stripped-down version of "What's Going On" that Motown refused to release. But it's the original LP (heard here in remastered form) that transfixes: Listen to Gaye's unearthly multitracked voice over the spacey gospel of "God Is Love." Greatest protest album ever made? Most stirring soul-music symphony? Yes and yes. And then some.

The 100 Greatest Singers of All Time: Marvin Gaye

“Help Me”

Joni Mitchell wrote and recorded this song for her album Court and Spark, but she had to switch from her regular band to make the song sound exactly the way she wanted. "I had attempted to play my music with rock & roll players," she told Rolling Stone. "They’d laugh, 'Awww, isn't that cute? She's trying to teach us how to play.'" Mitchell switched to a jazz band, Tom Scott’s L.A. Express, and scored the biggest hit of her career in the process.