Christina María Aguilera

• Themes and musical style
The constant theme in Aguilera's music and lyrics is love, although she has written on other subjects including spirituality, female empowerment, and grief. Aguilera has also written about her childhood in two of her records which dealt with domestic abuse. In an interview Aguilera admitted she feels responsible to reveal her most vulnerable feelings and to share the darker sides of her life adding "People that can relate might not feel as alone in the circumstance." She has been noted to constantly changing her sound in her music and lyrical content. Originally marketed as a bubblegum pop singer during the late 90s pop scene, she quickly departed into a broad range of musical genres for her follow-up album Stripped. A review states, "Clearly afflicted with Premature Serious Artist Syndrome, Aguilera wants to demonstrate the range of her interests – vampy soul, quasi-metal, piano-bar intimacy, quiet-storm R&B, bounce-bounce hip-hop, and semi-exotic rock, all of it dutifully accomplished."
The majority of the songs are characterized by Aguilera's loud vocals, though she has used breathy and soft vocals. Her 2006 release, Back to Basics included producer DJ Premier. The New York Times exclaims, "Her decision to work with the low-key DJ Premier was also a decision to snub some of the big-name producers on whom pop stars often rely." Aguilera has often cited that she prefers working with producers that are not in popular demand, saying "I don't necessarily go to the main people that are the No. 1 chart-toppers in music." The album included live instrumentation and samples of past jazz and soul records. Some tracks on the album included non-traditional forms of pop music such as swing jazz and big band, drawing comparisons to Madonna's I'm Breathless and the musical film Cabaret. Her first feature film, Burlesque, influenced by Cabaret, featured mainstream producers Tricky Stewart and Danja on the soundtrack where several established songs were updated and worked into dance numbers, a style similar to 2001's Moulin Rouge! "Diamonds Are a Girl's Best Friend" was performed by Aguilera in the film, a musical number also performed by Nicole Kidman in Moulin Rouge!