British singer Ed Sheeran has appeared in a New York City court to deny that his song Thinking Out Loud copied Marvin Gaye’s song Let’s Get it On.

Heirs of Gaye’s co-writer, Ed Townsend, argue that Sheeran, Warner Music Group and Sony Music Publishing owe them money for allegedly stealing the song.

As the case opened, a lawyer called Sheeran’s use of Gaye’s lyrics at his concerts a “smoking gun”.

The 32-year old Grammy winner, testified that he did not copy from Gaye’s 1973 hit.

Earlier on Tuesday, Sheeran’s lawyer argued that both songs are distinct from each other and that no artist should be allowed to “monopolise” commonly used musical chord progressions.

This is not the only trial Sheeran is facing over Thinking Out Loud, which went to number one in the UK in 2014 and won song of the year at the Grammy Awards in 2016. A company called Structured Asset Sales (SAS), which has acquired a portion of the estate of Let’s Get It On, has filed a second case, which currently on pause, while a separate suit by another portion of Townsend’s estate is awaiting trial.