Kelly Brianne Clarkson (born April 24, 1982) is an American singer, songwriter and occasional actress. Clarkson came into prominence after becoming the winner of the inaugural season of the television series American Idol in 2002 and later was the runner-up in the television special World Idol in 2003.

In 2003, Clarkson released her debut album, Thankful, which was a commercial success and established herself in the pop music industry. The release of its first single, "A Moment Like This" (2002), broke The Beatles' record for the biggest leap to number one, from 52, in the history of the Billboard Hot 100 chart. After parting ways with her management, Clarkson developed a more rock-oriented music with the release of her critically acclaimed sophomore album, Breakaway (2004), which sold more than 12 million copies worldwide and which garnered Clarkson more worldwide success as a pop rock artist. The album's single, "Because of You" (2005), became the best-selling single by an Idol contestant worldwide. In 2007, Clarkson took full creative control for her third album My December, which had a more rock-inspired sound and was met with controversy and moderate success. Clarkson later returned to a more pop-oriented sound with All I Ever Wanted (2009), which became a commercial and critical success. The album's lead single, "My Life Would Suck Without You" (2009), surpassed "A Moment Like This"'s record for the biggest leap to number one on a single week in the history of the Billboard Hot 100 Chart, a milestone it still holds today. Furthermore, it also became her first number one single in the United Kingdom. Clarkson's fifth studio album, Stronger, was released in 2011, containing elements from synthpop, R&B and country music. The album's single, "Stronger (What Doesn't Kill You)" (2012), became her longest number one single and eventually became her best-selling single in the United States.

Stefani Joanne Angelina Germanotta (/ˈstɛfəniː dʒʌrməˈnɑːtə/ STE-fə-nee jurr-mə-NAH-tə; born March 28, 1986), known by her stage name Lady Gaga, is an American singer and songwriter. Born and raised in New York City, she primarily studied at the Convent of the Sacred Heart and briefly attended New York University's Tisch School of the Arts before withdrawing to focus on her musical career. She began performing in the rock music scene of Manhattan's Lower East Side, and was signed with Streamline Records by the end of 2007. During her employment as a songwriter for the record company, her vocal abilities captured the attention of recording artist Akon, who signed her to his label Kon Live Distribution.

Lady Gaga came to prominence as a recording artist following the release of her debut album The Fame (2008), which was a critical and commercial success that topped charts around the world and included the international number-one singles "Just Dance" and "Poker Face". After embarking on the The Fame Ball Tour, she followed the album with The Fame Monster (2009), which spawned the worldwide hit singles "Bad Romance", "Telephone" and "Alejandro". The album's success allowed her to embark on the eighteen-month long Monster Ball Tour, which later became one of the highest-grossing concert tours of all time. Her most recent album Born This Way (2011) topped the charts of most major markets and generated more international chart-topping singles, including "Born This Way", "Judas" and "The Edge of Glory". Besides her musical career, she involves herself with humanitarian causes and LGBT activism.

Avril Ramona Lavigne (pronunciation: /ˈævrɨl ləˈviːn/; AV-ril lə-VEEN; born 27 September 1984) is a Canadian singer-songwriter. She was born in Belleville, Ontario, but spent most of her youth in the small town of Napanee. By the age of 15, she had appeared on stage with Shania Twain; by 16, she had signed a two-album recording contract with Arista Records worth more than $2 million. In 2002, when she was 17 years old, Lavigne broke onto the music scene with her debut album Let Go.

Let Go made Lavigne the youngest female soloist to reach No. 1 in the UK, and the album was certified four-times platinum by the Recording Industry Association of America. By 2009, over 16 million copies had been sold worldwide. Her breakthrough single, "Complicated", peaked at No. 1 in many countries around the world, as did the album Let Go. Her second album, Under My Skin, was released in 2004 and was her first album to peak at No. 1 on the U.S. Billboard 200, eventually selling more than 10 million copies worldwide. The Best Damn Thing, Lavigne’s third album, was released in 2007, becoming her third No. 1 album in the UK Albums Chart and featuring her first U.S. Billboard Hot 100 No. 1 single, "Girlfriend". Lavigne has scored six number-one singles worldwide, including "Complicated", "Sk8er Boi", "I'm with You", "My Happy Ending", "Nobody's Home", and "Girlfriend". With more than 30 million copies of her albums sold worldwide, Lavigne is one of the top-selling artists releasing albums in the U.S., with over 10.25 million copies certified by the RIAA. Her fourth studio album, Goodbye Lullaby, was released in March 2011. Goodbye Lullaby gave Lavigne her fourth top 10 album on the U.S. Billboard 200 and the UK Albums Chart and her third No. 1 album in both Japan and Australia. Three months after the release of Goodbye Lullaby, Lavigne began work on her fifth album, which will be released on Epic Records following her departure from RCA Records.