In a lot of cases, plagiarism is clear and may violate a copyright. If someone steals a text entirely and tries to pass it off as their own, that's plagiarism. They stole the content. When you compare the two, they look identical.
In art, the lines can get a bit more blurry. Artists often pay homage to older works as a way of acknowledging their greatness and their influence. However, when do things go too far?
That's the question many songwriters are asking. For instance, Ed Sheeran has been accused of copying Marvin Gaye. Sheeran's song is called "Thinking Out Loud," and he plans to defend its legitimacy in court. Gaye's classic song is called "Let's Get It On."
In some ways, it is even harder for professional songwriters who craft songs for pop stars. One man, who has written songs for superstars like Rihanna, Beyonce and Madonna, said that he is so worried about it that he often second-guesses the things he writes, worrying that certain lyrics or melodies may be too close to other songs. It's hard, he said, to locate that line.
And he doesn't like it. It can hamper the creative process, which needs to go as smoothly as possible for someone in his position to have the success that they are used to having. "I shouldn't be thinking about legal precedent when I am trying to write a chorus," he quipped.
Cases like these show just how complex copyright claims can get. If you find yourself involved in one of these cases, make sure you know exactly what legal steps you need to take.