Derivative Work: A new work derived from one or more pre-existing works, such as a remix of a song, acoustic version, or a song based on a poem, etc., and is primarily a US copyright term.
For derivative works, the original copyright holders may have a claim in the new version even if they are not the creators of the derivative work. A copyright owner reserves the right to authorize a "derivative work" based upon one or more pre-existing works, such as a translation, musical arrangement, dramatization, fictionalization, motion picture version, sound recording, a remix, art reproduction, abridgment, condensation, or any other form in which a work may be recast, transformed, or adapted.
A DIY songwriter decides to pay homage to their favorite song - 'Yesterday' by Paul McCartney - in an upcoming gig. In their version, they perform the song as an acoustic version and only sing the first verse and chorus as a transition into a new song they just released.
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