Avril Lavigne is pop's presiding mean girl, sneering and snarling like a punk kewpie doll with Tourette's over some of the most sticky-sweet melodies ever to hit the Billboard charts. "What the Hell" is Avril in a nutshell: Co-written by Max Martin, it's an anthem about a good girl who goes on a crazy-bender, staying out late, swapping boys and exacting psychological revenge. She starts out defiant ("All I want is to mess around") and quickly turns vicious: "I am messing with your head/When I'm messing with you in bed." (In fairness, the dude has been pretty neglectful.) The music is easily some of Avril's catchiest yet, with piping garage-rock organs, a pogoing, do-the-frug beat and a soaring singalong chorus. It's strychnine disguised as bubblegum.

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“Everyday People”

"Everyday People" managed to trailblaze in two different ways -- it was one of the first pop hits to deal with the subject of racial harmony, and it utilized Larry Graham's "slap" technique on the bass guitar, which would soon be copied by countless other bassists. Graham once said about his pulsating style, "I'd never done that before … that's where the freedom of creativity came in for the band, that we'd be allowed to do that." In 1978, the song's line "Different strokes for different folks" would be borrowed for the title of the hit television show Diff'rent Strokes.