Music recording sales certification is a system of certifying that a music recording has shipped or sold a certain number of copies, where the threshold quantity varies by type (such as: album, single, music video) and by nation or territory (See also: List of music recording certifications).

Almost all countries follow variations of the RIAA certification categories, which are named after precious materials. The thresholds below are used in the United States and United Kingdom only. For other countries definitions, see List of music recording certifications:

The number of sales or shipments required for these awards depends upon the population of the territory in which the recording is released. Typically, they are awarded only to international releases and are awarded individually for each country in which the album is sold. Different sales levels, some perhaps 10 times lower than others, may exist for different music media (for example: videos versus albums, singles, or downloads).

Originally applied to LP records, certification is now most commonly awarded for compact disc (CD) sales.^{[citation needed]} Certification is often awarded cumulatively, and it is possible for a single album to be certified silver, gold, and platinum in turn. An album that becomes platinum twice over is said to be "double-platinum"; three-times over, "triple-platinum", etc., which can all be generalized with the term "multi-platinum". Artists can also become multi-platinum sellers if they have at least two albums in the same territory both going single Platinum. A poor-selling record is often jokingly said to have "sold lead" (the heavy metal lead), in contrast to attaining high status as a gold or platinum album.

Sound recording and reproduction is an electrical or mechanical inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording. Acoustic analog recording is achieved by a small microphone diaphragm that can detect changes in atmospheric pressure (acoustic sound waves) and record them as a graphic representation of the sound waves on a medium such as a phonograph (in which a stylus senses grooves on a record). In magnetic tape recording, the sound waves vibrate the microphone diaphragm and are converted into a varying electric current, which is then converted to a varying magnetic field by an electromagnet, which makes a representation of the sound as magnetized areas on a plastic tape with a magnetic coating on it. Analog sound reproduction is the reverse process, with a bigger loudspeaker diaphragm causing changes to atmospheric pressure to form acoustic sound waves. Electronically generated sound waves may also be recorded directly from devices such as an electric guitar pickup or a synthesizer, without the use of acoustics in the recording process other than the need for musicians to hear how well they are playing during recording sessions.

Christina María Aguilera (born December 18, 1980) is an American recording artist and actress. Aguilera first appeared on national television in 1990 as a contestant on the Star Search program, and went on to star in Disney Channel's television series The Mickey Mouse Club from 1993 to 1994. Aguilera signed to RCA Records after recording "Reflection", the theme song for the animated film Mulan (1998).

In 1999, Aguilera came to prominence following her debut album Christina Aguilera, which was a commercial success spawning three number one singles on the Billboard Hot 100—"Genie in a Bottle", "What a Girl Wants", and "Come On Over Baby (All I Want Is You)." Her sophomore and her debut Latin-pop album, Mi Reflejo (2000), a Christmas third studio album, My Kind of Christmas (2000), and several collaborations followed which garnered Aguilera worldwide success, though she was displeased with her lack of input in her music and image. After parting from her management, Aguilera took creative control over her fourth studio album, Stripped (2002). The album's second single, "Beautiful", was a commercial success and helped the album's commercial performance amidst controversy over Aguilera's image. Aguilera followed up Stripped with the soul, jazz and blues inspired, Back to Basics (2006), released to positive critical acclaim. The album produced three singles "Ain't No Other Man", "Hurt" and "Candyman". Four years later Aguilera released her sixth studio album, Bionic (2010), which incorporated aspects of R&B, electropop, and synthpop and was met with mixed reviews and low sales. Aguilera's seventh studio album is set to be released in 2012.