Katy Perry's "Dark Horse" was co-written by Sarah Hudson, who was a member of the pop group Ultraviolet Sound. Though Sarah isn't related to Katy (whose real name is Katy Hudson), she is the first cousin of another famous person with the same name, the actress Kate Hudson.
Buddy Holly got the title for his hit song "That'll Be The Day" from a phrase John Wayne repeats in the 1956 movie The Searchers.
Sia Furler wrote "Titanium" and wanted to give the tune to Katy Perry. She turned it down, so David Guetta recorded it instead using Sia's original demo guide vocal. It became a big hit, especially in the UK, where it went to #1.
"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.
The first single to simultaneously top the UK and US charts was The Everly Brothers' "Cathy's Clown" in May 1960.
Kesha (known at the time as Ke$ha) was still pretty wild when she released her song "Crazy Kids" in 2012. It's about one of her birthday parties that got a little out of hand.
Famous songs that lent their titles - and in some cases storylines - to movies.
Doubt led to drive for Francis, who still isn't sure why one of Status Quo's biggest hits is so beloved.
The top Contemporary Christian artist of all time on song inspirations and what she learned from Johnny Carson.
He wrote "She Blinded Me With Science" so he could direct a video about a home for deranged scientists.
Zac tells the story of Hanson's massive hit "MMMbop," and talks about how brotherly bonds effect their music.
Graham Nash tells the stories behind some of his famous songs and photos, and is asked about "yacht rock" for the first time.