There have been countless accusations of plagiarism in recent years, with many high-profile cases making it to court in the US.
Now Katy Perry has become embroiled in a similar case after a judge in Los Angeles ruled that the pop star had 'improperly copied' a Christian rap song.
A nine-person jury concluded that Perry's 2014 single 'Dark Horse' had infringed the copyright of 'Joyful Noise', which was released by Marcus Gray under the name Flame in 2009. The case was originally brought against her five years ago.
The jury found all six songwriters of the song - including Perry, rapper Juicy-J and lyricist Sarah Hudson - liable.
Gray's attorneys had argued that the beat and instrumental line that is the basis of most of 'Dark Horse' was 'substantially similar' to that of 'Joyful Noise'. Perry's attorneys refuted this accusation, saying that they were "trying to own basic building blocks of music, the alphabet of music that should be available to everyone."
The case will now proceed to the 'penalty' phase, where it will be decided how much the defendants owe Marcus Gray for the infringement.
What do you think - a clear case of ripping it off, or simple coincidence?