1. "Billie Jean"
Michael Jackson's greatest song sums up all the contradictions in his music: youthful exuberance, tortured nerves, pure physical grace. As he told Rolling Stone at the time, "Billie Jean" reflected his own sexual paranoia as a 24-year-old megastar: "Girls in the lobby, coming up the stairway. You hear guards getting them out of elevators. But you stay in your room and write a song. And when you get tired of that, you talk to yourself. Then let it all out onstage." Although "Billie Jean" was one of the first songs MJ wrote for Thriller, he and Quincy Jones kept tinkering with it right up to the final mastering stage. The miles-deep bass line comes from funk stalwart Louis Johnson of the Brothers Johnson. Drummer Ndugu Chancler cut the drum track over Jackson's original drum-machine beat, and jazz vet Tom Scott played the eerie lyricon solo. At five minutes long, "Billie Jean" has the sleek sweep of disco, yet a classic-rock sense of epic scale. Quincy Jones worried the intro was too long: "But [Jackson] said, 'That's the jelly, that's what makes me want to dance.' " The world has been dancing to "Billie Jean" ever since.