Katheryn Elizabeth Hudson (born October 25, 1984), known professionally as Katy Perry, is an American singer, songwriter, and television judge. After singing in church during her childhood, she pursued a career in gospel music as a teenager.

Perry signed with Red Hill Records and released her debut studio album Katy Hudson under her birth name in 2001, which was commercially unsuccessful. She moved to Los Angeles the following year to venture into secular music after Red Hill ceased operations and she subsequently began working with producers Glen Ballard, Dr. Luke, and Max Martin.

After adopting the stage name Katy Perry and being dropped by The Island Def Jam Music Group and Columbia Records, she signed a recording contract with Capitol Records in April 2007.

Mariah Carey (born March 27, 1969 or 1970) is an American singer, songwriter, actress, and record producer. Referred to as the "Songbird Supreme" by Guinness World Records, she is noted for her five-octave vocal range, melismatic singing style, and signature use of the whistle register.

She rose to fame in 1990 after signing to Columbia Records and releasing her eponymous debut album, which topped the U.S. Billboard 200 for eleven consecutive weeks. Soon after, Carey became the only artist ever to have their first five singles reach number one on the U.S. Billboard Hot 100 chart, from "Vision of Love" to "Emotions".

Taylor Alison Swift is an American singer-songwriter. She is known for narrative songs about her personal life, which have received widespread media coverage. At age 14, Swift became the youngest artist signed by the Sony/ATV Music publishing house and, at 15, she signed her first record deal.

Her 2006 eponymous debut album was the longest-charting album of the 2000s in the US. Its third single, "Our Song", made her the youngest person to single-handedly write and perform a number-one song on the Billboard Hot Country Songs chart. Swift's second album, Fearless, was released in 2008.

Buoyed by the pop crossover success of the singles "Love Story" and "You Belong with Me", it became the US' best-selling album of 2009 and was certified diamond in the US. The album won four Grammy Awards, and Swift became the youngest Album of the Year winner.