Music plagiarism is the use or close imitation of another author's music while representing it as one's own original work. Plagiarism in music now occurs in two contexts – with a musical idea (that is, a melody or motif) or sampling (taking a portion of one sound recording and reusing it in a different song). For a legal history of the latter see Sampling.

Any music that follows rules of a Musical scale is limited by the ability to use a small number of notes. The 7 note diatonic scale is the foundation of the European musical tradition.
No artist denies the existence of, and relation between, musical genres. In addition, all forms of music can be said to include patterns. Algorithms (or, at the very least, formal sets of rules) have been used to compose music for centuries; the procedures used to plot voice-leading in Western counterpoint, for example, can often be reduced to algorithmic determinacy.

For these reasons, accidental or 'unconscious' plagiarism is possible. As well, some artists abandon the stigma of plagiarism altogether. Shostakovich perhaps commented sarcastically on the issue of musical plagiarism with his use of "We Wish You a Merry Christmas," an instantly recognizable tune, in his Prelude No. 15 in D Flat, Op. 87.^[1]

According to the U.S. copyright law, in the absence of a confession, musicians who accuse others of stealing their work must prove "access" — the alleged plagiarizer must have heard the song — and "similarity" — the songs must share unique musical components.^[2] though it is difficult to come to a definition of what is "similarity".

Even if a piece of music is in the public domain and thus not protected by copyright, it may still be plagiarism to copy a portion (or all) of it without attribution. There are many changes in the creation, content, dissemination and consumption of popular music in the 21st Century.

Plagiarism is relevant to different musical styles in different ways.

In classical music, software exists that automatically generates music in the style of another composer, using musical analysis of their works. Most notably, David Cope^[3] has written a software system called "Experiments in Musical Intelligence" (or "EMI") that is capable of analyzing and generalizing from existing music by a human composer to generate novel musical compositions in the same style. EMI's output is convincing enough to persuade human listeners that its music is human-generated to a high level of competence.

Rock music, melodic music, and other forms of popular music and folk music tend to select ("borrow") one or two melodies' (verse and chorus) and build a new song from these elements. Variety may occur in the phrasing, lyrics and song structure, though original content in pop music may be quite low compared with other genres.^[4]

Sampling has been an area of contention from a legal perspective. Early sampling artists simply used portions of other artists' recordings, without permission; once rap and other music incorporating samples began to make significant money, the original artists began to take legal action, claiming copyright infringement. Some sampling artists fought back, claiming their samples were fair use (a legal doctrine in the USA that is not universal). International sampling is governed by agreements such as the Berne Convention for the Protection of Literary and Artistic Works and the WIPO Copyright and Performances and Phonograms Treaties Implementation Act.

Today, most mainstream artists obtain prior authorization to use samples, a process known as "clearing" by gaining permission to use the sample and, usually, paying an up-front fee and/or a cut of the royalties to the original artist. Unfortunately, independent bands, lacking the funds and legal assistance to clear samples, are at a disadvantage unless they seek the services of a professional sample replay company or producer.

Recently, a movement — started mainly by Lawrence Lessig of free culture – has prompted many audio works to be licensed under a Creative Commons license that allows for legal sampling of the work provided the resulting work(s) are licensed under the same terms.

Most cases of alleged plagiarism are settled out of court. Most artists try and settle for costs that will be less than defending costs. Since the 1850s federal courts have published fewer than 100 opinions dealing with this issue.^[5] The Columbia Law School Library's Music Plagiarism Project provides information on many cases over the decades, with a few dating back to the 19th century.

• George Harrison was successfully sued in a prolonged suit that began in 1971 for plagiarizing the Chiffons' "He's So Fine" for the melody of his own "My Sweet Lord." ^[6]

• In early 2007, Timbaland was alleged to have plagiarized several elements (both motifs and samples) in the song "Do It" on the 2006 album Loose by Nelly Furtado without giving credit or compensation. See 2007 Timbaland plagiarism controversy.

• In early 2006, the writers of Lee Hyori's song "Get Ya" were accused of plagiarizing Britney Spears' 2005 song "Do Somethin'". This eventually led Lee Hyori to stop promoting the song and contributed to the failure of the song and its album, Dark Angel.

• In 2005, Belgian songwriter Salvatore Acquaviva won a judgment against Madonna, claiming that her 1998 hit, "Frozen" had been lifted from his early-80s song, "Ma View Fout L'camp". The judge declined to award damages, but did order the withdrawal of all remaining discs for sale and barred the song from airplay on Belgian TV and radio.^[7]

• During the mid-1930s, Ira Arnstein became convinced that major pop songwriters had been illegally copying his work. During 1936-46 he brought forth five plagiarism lawsuits though none proved successful.

• In 1994 John Fogerty was sued for self plagiarism after leaving Fantasy Records and pursuing a solo career with Warner Brothers. Fantasy still owned the rights to the Creedence Clearwater library and sound. Saul Zaentz, the owner of Fantasy, claimed Fogerty's song "Old Man Down the Road" was a musical copy of the Creedence song "Run Through the Jungle". The court made a landmark decision when it ruled that an artist cannot plagiarize himself.

• In 1993 Killing Joke sued Nirvana alleging that the riff for the latter's song "Come as You Are" was copied from the riff for their song "Eighties". The lawsuit was dropped after the sudden death of Nirvana frontman Kurt Cobain.^[8]

• In 1993 Cottrill claimed that Britney Spears’s "Can’t Make You Love Me" also misappropriated substantial melodic material from their "What You See is What You Get". The court was skeptical on the question of defendant’s access to the plaintiff’s work.^[9]

• Ronald H. Selle, sued the Bee Gees, alleging their 1977 hit, "How Deep Is Your Love", stole the melody of his own never-released 1975 song, "Let It End". The Bee Gees eventually prevailed after an appeal.^[10]

The following are accusations of plagiarism appearing in notable media—

• A lawsuit filed by 70s pop band Rubinoos alleges Avril Lavigne stole one of their songs and reworked it into her bestselling single "Girlfriend".^[11]

• A portion of the Bruce Springsteen single, "Radio Nowhere." sounds similar to Tommy Tutone's 1982 hit, "867-5309/Jenny." Tommy Heath's response was "I'm really honored at a similarity, if any, I think there's too much suing in the world now"^[12]

• The New York Post reported remarkable similarities between the Red Hot Chili Peppers' "Dani California" and Tom Petty's "Mary Jane’s Last Dance" could turn into a lawsuit. Petty responded in a Rolling Stone interview:

...a lot of RocknRoll songs sound alike. Ask Chuck Berry. The Strokes took "American Girl" [for their song "Last Nite"], and I saw an interview with them where they actually admitted it. That made me laugh out loud. I was like, "OK, good for you." It doesn’t bother me.^[13]

• In the bollywood industry, accusations of plagiarism are so high that several websites[1][2] exist solely to archive public accusations, of which very few receive legal attention.^[14]

iTunes has found cases of musical plagiarism using software that automatically identifies a CD's track information when it's loaded, most notably the many instances with pianist Joyce Hatto.^[15]

• Credit (creative arts)
• List of plagiarism controversies
• Plagiarism detection
• Source criticism

• A Mathematical Look at Musical Plagiarism by Frank Behrens, Art Times, May, 2004
• UCLA Law Copyright Infringement Project
• J. Michael Keyes, "Musical Musings: The Case for Rethinking Music Copyright Protection", 10 Mich. Telecomm. Tech. L. Rev. 407 (2004), available at [3]