A mashup or bootleg (also mesh, mash up, mash-up, blend and bastard pop/rock) is a song or composition created by blending two or more pre-recorded songs, usually by overlaying the vocal track of one song seamlessly over the instrumental track of another. To the extent that such works are "transformative" of original content, they may find protection from copyright claims under the "fair use" doctrine of copyright law.

Mashups are known by a number of different names:

In addition, more traditional terms such as "edits" or (unauthorized) "remixes" are favored by many "bootleggers" (also known as 'leggers).^{[citation needed]}

The practice of assembling new songs from purloined elements of other tracks stretches back to the beginnings of recorded music. If one extends the definition beyond the realm of pop, precursors can be found in musique concrète, as well as the classical practice of (re-)arranging traditional folk material and the jazz tradition of reinterpreting standards. In addition, many elements of mashup culture have antecedents in hip hop and the DIY ethic of punk as well as overlap with the free culture movement.

Music is an art form whose medium is sound and silence. Its common elements are pitch (which governs melody and harmony), rhythm (and its associated concepts tempo, meter, and articulation), dynamics, and the sonic qualities of timbre and texture. The word derives from Greek μουσική (mousike; "art of the Muses").

The creation, performance, significance, and even the definition of music vary according to culture and social context. Music ranges from strictly organized compositions (and their recreation in performance), through improvisational music to aleatoric forms. Music can be divided into genres and subgenres, although the dividing lines and relationships between music genres are often subtle, sometimes open to individual interpretation, and occasionally controversial. Within "the arts", music may be classified as a performing art, a fine art, and auditory art. There is also a strong connection between music and mathematics.

To many people in many cultures, music is an important part of their way of life. Ancient Greek and Indian philosophers defined music as tones ordered horizontally as melodies and vertically as harmonies. Common sayings such as "the harmony of the spheres" and "it is music to my ears" point to the notion that music is often ordered and pleasant to listen to. However, 20th-century composer John Cage thought that any sound can be music, saying, for example, "There is no noise, only sound." Musicologist Jean-Jacques Nattiez summarizes the relativist, post-modern viewpoint: "The border between music and noise is always culturally defined—which implies that, even within a single society, this border does not always pass through the same place; in short, there is rarely a consensus ... By all accounts there is no single and intercultural universal concept defining what music might be."

Jordan Roseman (aka DJ Earworm) is a San Francisco-based mashup artist who has achieved recognition for his technically sophisticated, songwriting oriented music and video mashups. His annual “United State of Pop” mashups, short mixes featuring the top 25 songs of the year according to Billboard magazine, have reached the Top 100 for national radio play.

Roseman was born into a big family of musicians and raised in eastern Iowa and Evanston, Illinois. In his early life, he played piano and produced original electronic music on a computer, later majoring in music theory and computer science at the University of Illinois. He began using ACID recreationally in 2003. After encouragement from DJ Adrian at Club Bootie, Roseman created the moniker DJ Earworm ("earworm" referencing a song that repeats uncontrollably in one's mind) and began releasing mashups via a website.

DJ Earworm has a unique mashup style that consists of a compositional, songwriting approach. He gradually layers samples on top of one another, matching keys and subtly altering melodies. His mashups often convey an entirely new meaning than the original material, such as a political message in “No More Gas”. He has been contrasted with mashup artist Girl Talk, who has a more DJ-oriented style.

Aloe Blacc (born Egbert Nathaniel Dawkins III; January 7, 1979) is an American soul singer, rapper and musician. He is married to Australian rapper Maya Jupiter.

Blacc was born in Orange County, California to Panamanian parents. He began his music career in 1995 as a rapper in the hip hop duo Emanon with producer Exile.

By the late 1990s, Blacc was part of the duo Emanon and joined the group Lootpack on tour in Europe. The duo released six albums. This led to Blacc working with the French Jazz group Jazz Liberatorz. He released an album at the end of the 1990s.

In 2003, Blacc signed with Stones Throw Records and began a solo career. On July 11, 2006, he released his first LP album, Shine Through, on CD, vinyl record and online (on the Stones Throw website).

He then toured across Europe and the U.S. with Emanon, while working on his second solo album.

In 2009, Blacc collaborated with the Japanese hip hop producer Cradle. They called themselves Bee.

In 2010, Blacc released his second album, Good Things, on Stones Throw records. The album was produced by Jeff Dynamite and Leon Michels for Truth & Soul Productions.

Selena Marie Gomez (born July 22, 1992) is an American actress and singer best known for portraying Alex Russo in the Emmy Award-winning Disney Channel television series Wizards of Waverly Place. She subsequently ventured into feature films and has starred in the television movies Another Cinderella Story, Wizards of Waverly Place: The Movie, and Princess Protection Program. She made her starring theatrical film debut in Ramona and Beezus.

Her career has expanded into the music industry; Gomez is the lead singer and founder of the pop band Selena Gomez & the Scene, which has released three RIAA Gold certified studio albums, Kiss & Tell, A Year Without Rain, and When the Sun Goes Down, spawned three RIAA Platinum certified singles, "Naturally", "Who Says" and "Love You Like a Love Song" and charted four No. 1 Billboard Hot Dance Club Songs. Gomez has also contributed to the soundtracks of Tinker Bell, Another Cinderella Story, Wizards of Waverly Place, and Shake It Up after signing a record deal with Hollywood Records.