Declan Patrick MacManus (born 25 August 1954), known as Elvis Costello, is an English singer-songwriter. He came to prominence as an early participant in London's pub rock scene in the mid-1970s and later became associated with the punk/New Wave genre. Steeped in word play, the vocabulary of Costello's lyrics is broader than that of most popular songs. His music has drawn on many diverse genres; one critic described him as a "pop encyclopedia," able to "reinvent the past in his own image".
Costello was born Declan Patrick MacManus in St Mary's Hospital, London, the son of Lilian Alda (nee Ablett, b. 1927, Liverpool) and Ross MacManus, a musician and bandleader. He is of Irish heritage. Costello lived in Twickenham, attending Hounslow Secondary Modern School, which is now St Mark's Catholic Secondary School, in neighbouring Hounslow. With a musically inclined father (who was a jazz trumpeter and sang with The Joe Loss Orchestra), Costello's first broadcast recording was alongside his dad in a television commercial for R. White's Lemonade (I'm a Secret Lemonade Drinker). His father wrote and sang the song; Costello provided backing vocals. The advertisement won a silver award at the 1974 International Advertising Festival.
Costello moved with his Liverpool-born mother to Birkenhead in 1971. There, he formed his first band, a folk duo called Rusty, with Allan Mayes. After completing secondary school at St. Francis Xavier's College, he moved back to London where he next formed a band called Flip City, which had a style in the pub rock vein. They were active from 1974 through to early 1976. Around this time, Costello adopted the stage name D.P. Costello. His father had performed under the name Day Costello, and Elvis has said in interviews that he took this name as a tribute to his father.

Katheryn Elizabeth Hudson (born October 25, 1984), better known by the stage name Katy Perry, is an American singer-songwriter, musician and actress. Born in Santa Barbara, California, and raised by Christian pastor parents; Perry grew up listening to only gospel music and sang in her local church as a child. After earning a GED during her freshman year of high school, she began to pursue a music career. She released a self-titled gospel album in 2001 as Katy Hudson which was deemed unsuccessful due to the closing of its record label that year. She later recorded an album with production team The Matrix and completed the majority of a solo album from 2004?2005, neither of which was released.