The composer of the opening guitar riff for Eminem's Lose Yourself has told a court the soundtrack of a New Zealand political ad is a "blatant rip-off".
Jeff Bass told the High Court in Wellington that the song - titled Eminem Esque and used by the ruling National Party during its 2014 election campaign - sounds like "Lose Yourself Lite".
He added: "It doesn't taste so good, though."
Eminem's music publisher Eight Mile Style is suing the National Party over its use of the song. The judge-only copyright infringement case started on Monday and is expected to last about six days.
The party has said it purchased the soundtrack for its TV ad from an Australian-based music supplier and does not believe it has infringed anyone's copyright.
Bass, who lives near Detroit and travelled to New Zealand to give evidence, used an acoustic guitar to strum the famous riff that opens the Oscar-winning 2002 song in front of eight lawyers and a judge in the courtroom.
He said he wrote the song with Eminem and Luis Resto over 18 months.
"I picked up a guitar and started playing that opening guitar chord," he said. "At that time, I didn't know if it was a song or not."
He said Eminem, aka Marshall Mathers III, put together a drum track but then they got stuck.
"It took him a number of months to author the perfect lyrics that were just right for the beat," Bass said.
He said they finished as Eminem completed work on his film 8 Mile.
"It really developed in a little studio we had set up in his trailer," Bass told the court. He said Resto replaced some of the guitar elements with keyboards to remove some of the rock feel of the song without losing the hip-hop tone.
Defence lawyers argue the musical composition of the song is not particularly original. One of them asked Bass if he considered the soundtrack Eminem Esque to be musically inferior.
"Being that it's a blatant rip-off, yes," Bass responded.
The lawyer asked if it was weaker because it was different: "It doesn't feel like Lose Yourself?"
"It doesn't feel like me playing Lose Yourself," Bass replied.
The lawyer asked Bass if agreed that the Led Zeppelin song Kashmir has a similar chord pattern.
"No. None whatsoever," Bass responded.
Judge Helen Cull asked Bass if the guitar strum he performed in the courtroom was common.
Bass said that while he had heard those chords played before, he had never heard them in that particular rhythm.
He said that by putting an accent on the third beat it was as if he was playing guitar and drums at the same time.
"The intention was to create a tense, hypnotic feeling," Bass said. "It starts playing, and never goes away. Along with that drum beat, it actually will hypnotise you, where you are feeling that something's going to happen."
AP