2.Pharrell helped write "Hollaback Girl" with Gwen Stefani for her 2004 album, Love. Angel. Music. Baby.
Listen to the song here:
3.Kelly Clarkson wrote "Tell Me a Lie" for One Direction's 2011 album, Up All Night.
Listen to the song here:
4.Linda Perry (from 4 Non Blondes) wrote "Beautiful" for Christina Aguilera's 2002 album, Stripped, and "Get the Party Started" for Pink's 2001 album, Missundaztood.
Listen to "Beautiful" here:
And listen to "Get the Party Started" here:
5.Miguel and Justin Timberlake helped write "Rocket" with Beyoncé for her 2013 self-titled album, Beyoncé.
Listen to the song here:
6.Prince wrote "Manic Monday" for the Bangles' 1986 album, Different Light.
Listen to the song here:
7.Bruno Mars helped write "All I Ask" with Adele for her 2015 album, 25.
Listen to the song here:
8.Harry Styles wrote "Just a Little Bit of Your Heart" for Ariana Grande's 2014 album, My Everything.
Listen to the song here:
9.Mariah Carey wrote Faith Hill's "Where Are You Christmas?" for the How the Grinch Stole Christmas soundtrack in 2000.
Listen to the song here:
10.Missy Elliott wrote "My Love Is Like...Wo" for Mýa's 2003 album, Moodring.
Listen to the song here:
11.Alicia Keys and Swizz Beatz wrote "Million Dollar Bill" for Whitney Houston's 2009 album, I Look to You.
Listen to the song here:
12.Christina Milian wrote "Play" for Jennifer Lopez's 2001 album, J.Lo.
Listen to the song here:
13.John Lennon helped write "Fame" with David Bowie for Bowie's 1975 album, Young Americans.
Listen to the song here:
14.Carole King wrote "(You Make Me Feel Like) a Natural Woman" for Aretha Franklin's 1968 album Lady Soul.
Listen to the song here:
15.And Sia wrote "Invincible" for Kelly Clarkson's 2015 album, Piece by Piece.