Ed Sheeran faces Marvin Gaye copyright trial in New York.

The trial for a lawsuit filed by the heirs of Ed Townsend, co-writer of Marvin Gaye's "Let's Get It On," against Ed Sheeran over alleged similarities between Sheeran's "Thinking Out Loud" and Gaye's song has begun in New York. Sheeran is expected to testify, and the trial is expected to last a week. The lawsuit alleges that Sheeran's song has "striking similarities" to "Let's Get It On" and "overt common elements" that violate their copyright. Sheeran's attorneys argue that the songs share an unprotectable chord progression that is freely available to all songwriters.