Sydney's Federal Court was alive with music as the writers of Australian hit Love Is In The Air began their copyright lawsuit against an American band and Air France.
Singer John Paul Young, who made the song one of the country's biggest pop hits which later featured in the movie Strictly Ballroom, was in court to support Harry Vanda who wrote it with the late George Young in 1977.
Vanda, George Young's estate, Boomerang Investments and two Australian copyright bodies are suing American duo Glass Candy, its songwriters Johnny Padgett and Lori Monahan, Kobalt Music Publishing and Air France.
Their barrister, Michael Hall SC, played Justice Nye Perram music videos on Monday showing John Paul Young performing the hit, Glass Candy performing their song Warm in The Winter and an Air France advertisement using part of the duo's version which includes the words France Is In The Air.
Mr Hall said the Australian song consists of the musical work and the lyrics, the product of both authors.
"We say the material was deliberately copied with writers very familiar with Love Is In The Air, who had that song in mind when they composed Warm in the Winter," he said.
If the judge was not satisfied it was deliberate, he argued, it was an unconscious reproduction.
The lawyer also said Vanda and Young never consented to their lyrics being changed including a time when a hair-care company proposed a Hair Is In The Air advertisement.
Richard Cobden SC, for Glass Candy and its two songwriters, said the case involved a major misunderstanding, noting "love is in the air" is a common phrase.
Padgett said he had never heard of the Vanda and Young song before Warm in The Winter, while Monahan said she did not think she had heard of it, the barrister said.
She had heard the phrase in a yoga class and told Padgett who was writing a song about cliches, he said.
Vanda testified to being shocked and horrified by the France Is In The Air change, accompanied by what Mr Cobden called "a little melodic fragment" of Love Is In the Air.
The barrister showed the court a deodorant advertisement which was accompanied by the song and showed frogs copulating and elderly gentlemen dying while having sex.
"I don't approve of it, but it doesn't shock and horrify me," Vanda said.
He said he had no idea of the prior existence of a song called Love Is In The Air penned by famous American composer-lyrist Stephen Sondheim..
Mr Cobden played a Volkswagen advertisement which had a couple in one car listening to the Vanda and Young song and a younger couple in another car listening to a rap version of it.
He noted the latter version had a change of lyrics to "Sitting in Your Love Seat Gasping For Air", which Vanda described as a "bastardisation" but said he was unaware if it had been approved.
The hearing continues.
© AAP 2019