"Womanizer" was Britney Spears' comeback song, going to #1 about 10 months after she was institutionalized to get treatment for addictions and mental health issues.
Avril Lavigne has a perfume named after her song "Black Star." It smells much better than her Sk8er Boi scent, which reeks of Axe body spray and road grime.
Rachel Platten refused to talk politics when her "Fight Song" became the anthem for Hillary Clinton's 2016 presidential campaign, a decision she came to regret.
"I Just Called To Say I Love You" is Stevie Wonder's best-selling single worldwide. It topped the Hot 100, AC, R&B and UK charts all in the same week.
Billy Joel's song "Allentown" was written as "Levittown," which is the town in Long Island where he grew up. He got the idea to change it after taking a trip to Pennsylvania.
"Santa Claus Is Coming To Town" was first recorded in 1934 by Eddie Cantor, but in 1962 it was one of the first hits for The Four Seasons, who became one of the most popular groups of that decade.
Tom stopped performing Thompson Twins songs in 1987, in part because of their personal nature: "Hold Me Now" came after an argument with his bandmate/girlfriend Alannah Currie.
How the American gangsta rappers made history by getting banned in the UK.
For songwriters, Johnny represents the American man. He has been angry, cool, magic, a rebel and, of course, marching home.
Medley looks back on "Unchained Melody" and "You've Lost That Lovin' Feelin'" - his huge hits from the '60s that were later revived in movies.
The lead singer/lyricist for Anberlin breaks down "Impossible" and covers some tracks from their 2012 album Vital.
Soul music legend Bill Withers on how life experience and the company you keep leads to classic songs like "Lean On Me."