One of Tom Petty's most personal songs is "Room At The Top," which he stopped performing because it brought back painful memories.
An unexpected guest vocal: Marianne Faithfull on the Metallica song "The Memory Remains." A star in the '60s, this collaboration helped revive her career.
References to David Bowie, Tom Waits and Allan Ginsburg are peppered into the Bush song "Everything Zen."
Bob Seger's song "Beautiful Loser" was inspired by book Leonard Cohen published in 1966 called Beautiful Losers.
"She Loves You" by The Beatles was the song that convinced Ozzy Osbourne to make music his life. The Beatles were a big influence on him because they were also poor kids from a small town in England.
"Coming Home" by Diddy - Dirty Money was originally iwritten for for T.I., who was getting out of prison at the time.
The guy who brought us "Stacy's Mom" also wrote the Jane Lynch Emmy song and Stephen Colbert's Christmas songs.
The lead singer of Everclear, Art is also their primary songwriter.
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.
Dave reveals the inspiration for "Feelin' Alright" and explains how the first song he ever wrote became the biggest hit for his band Traffic.
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."
When he joined Guns N' Roses in 1990, Matt helped them craft an orchestral sound; his mezzo fortes and pianissimos are all over "November Rain."