In popular music, a cover version or cover song, or simply cover, is a new performance or recording of a contemporary or previously recorded, commercially released song or popular song. It can sometimes have a pejorative meaning implying that the original recording should be regarded as the definitive or "authentic" version, and all others merely lesser competitors, alternatives or tributes (no matter how popular). Originally, Billboard and other magazines which track the popularity of the musical artists and hit tunes measured the sales success of the published tune, not just recordings of it. Later, they tracked the airplay that songs achieved, for which some cover versions are the more successful recording(s) of the particular song(s). Cover versions of well known, well liked, tunes are often recorded by new artists to achieve initial success when their unfamiliar original material would be less likely to be successful. Prior to the onset of Rock 'n' Roll in the 1950s, songs were published and several records of a song might be brought out by singers of the day, each giving it their individual treatment. Any singer who appeared to be copying an already successful version of the song would be viewed with disfavour. The trend, however, became for records to be produced, usually with particular background noises, and no other group would attempt a version.

Peter Gene Hernandez (born October 8, 1985), better known by his stage name Bruno Mars, is an American singer-songwriter and record producer. Raised in Honolulu, Hawaii by a family of musicians, Mars began making music at a young age. He performed in various musical venues in his hometown throughout his childhood. He graduated from high school and then moved to Los Angeles, California to pursue a musical career. Mars produced songs for other artists, joining production team The Smeezingtons.

Mars had an unsuccessful stint with Motown Records, but then signed with Atlantic Records in 2009. He became recognized as a solo artist after lending his vocals and co-writing the hooks for the songs "Nothin' on You" by B.o.B, and "Billionaire" by Travie McCoy. He also co-wrote the hits "Right Round" by Flo Rida featuring Ke$ha, and "Wavin' Flag" by K'naan. In October 2010, he released his debut album, Doo-Wops & Hooligans. Anchored by the worldwide number-one singles "Just the Way You Are" and "Grenade", the album peaked at number three on the Billboard 200. Mars was nominated for seven Grammys at the 53rd Grammy Awards, winning Best Male Pop Vocal Performance for "Just the Way You Are".

Pierre David Guetta (7 November 1967), known professionally as David Guetta (French pronunciation: [daˌvid ɡɛˈta]), is a French house music producer and DJ. Originally a DJ at nightclubs during the 1980s and 1990s, he co-founded Gum Productions and released his first album, Just a Little More Love, in 2002. Later, he released Guetta Blaster (2004) and Pop Life (2007). His 2009 album One Love included the hit singles "When Love Takes Over" (featuring Kelly Rowland), "Gettin' Over You" (featuring Chris Willis, Fergie & LMFAO) and "Sexy Bitch" (featuring Akon), the last becoming a top five hit in the United States and all three reaching #1 in the United Kingdom, as well as another internationally known single called "Memories" featuring Kid Cudi which became a top five hit in many countries. Guetta has sold over three million albums and 15 million singles worldwide. He is currently one of the most sought-after music producers. As at 2012 David Guetta is the world's most popular DJ, claiming the #1 poll position of the DJ Mag 100 popularity poll.

Greyson Michael Chance (born August 16, 1997) is an American pop rock singer and pianist whose April 2010 performance of Lady Gaga's "Paparazzi" at a sixth-grade music festival became a hit on YouTube, gaining over 45 million views as of December 3, 2011. Two of his original compositions, "Stars" and "Broken Hearts", gained over 5 and 7 million views respectively on his YouTube channel. His début single, "Waiting Outside the Lines", was released in October 2010. Chance's début album, Hold On 'Til the Night, was released on August 2, 2011.

Chance was born on August 16, 1997 in Wichita Falls, Texas, and currently resides in Edmond, Oklahoma. He is the youngest child of Scott and Lisa Chance. Chance has an eighteen-year-old sister, Alexa, and a twenty-year-old brother, Tanner, both of whom also do music. Chance began playing the piano at the age of 8 and has had three years of piano lessons. He, however, had no formal vocal training.

Of his inspiration, Chance said, "I love artists who are able to communicate their emotions through music and sing from the heart. That’s what I’m hoping to do with my songs." He was emboldened by Lady Gaga after seeing her performance of Paparazzi at the 2009 MTV Video Music Awards. He stated, "I was awestruck by her performance. I love her sense of drama and theatricality. Plus, she’s an amazing singer and piano player." Chance was also inspired by the artists Christina Aguilera, Augustana, John Legend, Elton John, and John Lennon.

Lindsey Stirling (born on September 21, 1986) is an American violinist, musician, dancer, performance artist, and composer. In 2010 she competed on the fifth season of America's Got Talent. Stirling is noted for her versatility performing music from country to hip hop.

At the age of 23 Stirling was a quarter-finalist on the fifth season of America's Got Talent where she was known as the ‘Hip Hop Violinist’. After Stirling's performance, Sharon Osbourne said, "Wow... we love you Lindsey!” and Piers Morgan called her performance "Electrifying!".

At the age of 5, after being influenced by the classic music records played by her father, Stirling requested the opportunity to learn and play the violin.

Stirling was classically trained through private lessons for 12 years. When she was 16, she joined a rock band with four friends called Stomp on Melvin. As part of her experience with Stomp on Melvin, Stirling wrote a solo violin rock song, and her performance helped her to win both the title of Arizona’s Jr. Miss in 2005 and the talent category of the National Jr. Miss Pageant. As of May 2, 2012, Stirling is 5'3" tall.