Lagy Gaga | Rihanna | Britney Spears | Katy Perry | Beyoncé
Carrie Underwood | Paramore | Kelly Clarkson | Bridgit Mendler | Ke$ha | Avril Lavigne | Adele | Miley Cyrus | P!nk
Jennifer Lopez | Christina Aguilera | Selena Gomez | Demi Lovato | Lady Antebellum | Mariah Carey | Miranda Lambert | One Direction | Alicia Keys | Shakira | Madonna | Justin Timberlake | Bruno Mars | Nicki Minaj | Justin Bieber | Carly Rae Jepsen | Cheryl Cole Last.fm
B-sides were a big thing back in the day. They would always appear on the other side of a vinyl single. Side A would be the single and side B would be a leftover track. They aren't very commonly used anymore, but artists like Pink still have b-sides and use them on CD singles, etc. A lot of UK acts also use them.