Here are some of the highlights:
Sam Smith Was Scared to Perform His No. 1 Hit "Stay With Me" on SNL
"Saturday Night Live is the thing that broke me in America, but I was very scared, and I actually begged my team and my label to not do it when we got the call," Smith tells Billboard. "I thought it would have more impact if I had a song out and on the radio. But I was so wrong. I had a story all of a sudden, and I was on people's iPods in the space of a week."
Iggy Azalea's No. 1 Hit "Fancy" (ft. Charli XCX) Was Almost Called Something Else
"When I wrote it, 'Fancy' was another song called 'Leave It.' I always knew it wasn't a hit, but it was a good song. It had such a solid beat and verses, but it needed something melodic to make it catchier, so I called Charli," Iggy explains. And the rest is history.
Jason Derulo's Sex n' Sax-Saturated No. 1 Hit "Talk Dirty" (ft. 2 Chainz) Came From Israel
While in Tel Aviv, Israel, A&R man Miles Beard picked up on a saxophone riff in a 2007 song called "Hermetico" from the Israeli band Balkan Beat Box. "Miles heard the song in January and played it for me on his phone in Los Angeles," says "Talk Dirty" producer Ricky Reed. "As soon as the saxophone riff came in, I knew it was a hit waiting to happen."
Meghan Trainor's No. 1 Hit "All About That Bass" Started as a Freestyle Rap
Meghan Trainor credits the birth of "All About That Bass" to producer Kevin Kadish's open mind. "I started the first verse freestyle because I was like, 'I rap,'" Trainor says. "When a little white girl walks in and says, 'I'm a rapper,' they don’t actually want you to rap. But he was all about it."
10 Best Albums of 2014
Minaj Wasn't Sure If Her No. 1 Hit "Anaconda" Was Going to Work, Until…
"I invited two of my best friends to the studio. I wanted to see their natural reactions to the song. And just the way they started this organic bopping, grooving on some playful girl stuff, I thought, 'OK, they feel like I feel, so I’m not crazy,'" Minaj says.
Read Billboard's Year in Music 2014 cover story when it's out Friday, Dec. 12.