The line, "Gotta keep 'em separated" in "Come Out And Play" by The Offspring came to lead singer Dexter Holland when he was a medical student and needed to keep bacteria samples away from each other.
Jay-Z's "Hard Knock Life (Ghetto Anthem)" is based on the song "It's A Hard Knock Life" from the Broadway play Annie.
"Truckin'" was written as the Grateful Dead were starting their long, strange trip, settling into a life of constant touring. They rode busses and holed up in modest hotels to stay grounded.
Ariana Grande's collaboration with Zedd, "Break Free" came about after the Russian-German producer overheard Grande performing at a label showcase while he was backstage, and he mentioned to his team that he wanted to work with her.
"Do The Bartman," released at the peak of Simpsons-mania, has uncredited backup vocals by Michael Jackson, who later appeared on the show.
Staind's big moment came in 1999 when lead singer Aaron Lewis played "Outside" on Limp Bizkit's Family Values tour. The live, acoustic version earned lots of radio play.
Smith breaks down some of his worship tracks as well as his mainstream hits, including "I Will Be Here For You" and "A Place In This World."
The Def Leppard frontman talks about their "lamentable" hit he never thought of as a single, and why he's juiced by his Mott The Hoople cover band.
The Brazilian rocker sees pictures in his riffs. When he came up with one of his gnarliest songs, there was a riot going on.
Kelly Keagy of Night Ranger tells the "Sister Christian" story and explains why he started sweating when he saw it in Boogie Nights.
Guitarist Tony Iommi on the "Iron Man" riff, the definitive Black Sabbath song, and how Ozzy and Dio compared as songwriters.
On Glen's résumé: hit songwriter, Facebook dominator, and member of Styx.
