Rihanna's 2012 hit "Diamonds" was written by Sia Furler, who two years later had a huge hit on her own with "Chandelier." Sia also wrote the David Guetta hit "Titanium."
The Foo Fighters song "Everlong" isn't about Kurt Cobain, but Dave Grohl's girlfriend at the time, Veruca Salt frontwoman Louise Post.
The song "Don't Worry Be Happy" doesn't use any instruments - it's all Bobby McFerrin using various parts of his body to make the sounds.
The Doobie Brothers' swampy #1 hit "Black Water" is about the Mississippi River, evoking the rafting adventures Mark Twain and Huckleberry Finn.
The Sam & Dave classic "Soul Man" was re-recorded by Sam Moore and Lou Reed for the 1986 movie Soul Man, about a white guy who pretends to be black so he can get a scholarship to Harvard.
The song "Sadeness" by Enigma (the one with the chanting monks), got its name from the French novelist Marquis de Sade, who believed sex had to be painful in order to be pleasurable - thus the word "sadism."
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.
Yngwie Malmsteen and Steve Vai were two of Graham's co-writers for some '80s rock classics.
Find out how God and glam metal go together from the Stryper frontman.
Waters tells the "Gypsy Woman" story, shares some of her songwriting insights, and explains how Dennis Rodman ended up on one of her songs.
A popular contemporary folk singer, Williams still remembers the sticky note that changed her life in college.
Kelly Keagy of Night Ranger tells the "Sister Christian" story and explains why he started sweating when he saw it in Boogie Nights.