Nathan Michael Wilkie, 19, of Browns Road, Timboon, appeared in the Warrnambool Magistrates Court last month to contest a charge of offensive behaviour.

The charge stems from the music he had playing on his car stereo while it was parked outside the Timboon supermarket - in particular songs by underground Melbourne rapper Kid Selzy.

Police prosecutor Sergeant Sandra Skilton told the court that the police officers "found it offensive and derogatory to females".

The court was read sample lyrics, including "shut your f ... mouth bitch, f ... motherf ..." and told that "f ..." and "motherf ..." were said continuously.

When confronted by police, it is alleged Mr Wilkie told them "you're a joke - go do some real police work".

The court heard that when he was asked to turn the music down, Mr Wilkie allegedly said "I don't give a shit".

"He was asked by police if he thought it was offensive - he said it was but it wasn't offensive to him," Sergeant Skilton told the court.

But defence counsel Amanda Chambers said her client and his mother, who was present during the incident and supporting her son, didn't accept the police's version of events.

"Even if we did completely accept the police summary, playing music as alleged doesn't consist of offensive behaviour," Ms Chambers said.

"The words used in the lyrics aren't that unusual and they're even used in exchanges between young people.

"In today's times, this language is not enough to constitute offensive behaviour.

"The only people who took offence were the police ? no one else came forward and made a complaint.

"This music is freely available to be purchased."

Police have even taken the step of ordering the CD - Kid Selzy's debut album The Creepshow - in preparation for the court case, which has been adjourned until June 11 for a contested hearing.

It is believed that Mr Wilkie's case is the first time anyone has been charged under Australian law with offensive behaviour for listening to music.

What constitutes offensive behaviour in legal terms is difficult to ascertain as judges take each case on its merits and the courtroom definition of "offensive" is one that has moved with the times.

As far back as 1973, a judge proclaimed the word "f ..." had lost "some of its offensiveness" due to its increased usage and everyday society.

Meanwhile, Kid Selzy is outraged by the incident.

"It's bullshit - the fact that the Victorian police are wasting taxpayers' money to take a kid to court for listening to music is beyond a joke," he said.

"Music is legal and he's been charged for doing something legal. Is driving around listening to a CD against the law these days? If it's legal to have a car stereo, it's legal to listen to what you want."

He said he didn't believe his music was offensive, just filled with profanities.

"If you read the lyrics, it's just my opinion and how I view shit," he said, adding that some people had described his music as "hateful".

"I don't pay attention to that.

"I know what I mean and the people who buy it know what I mean, and that's what really matters."

Selzy said music he found offensive was Britney Spears, Beyonce and Christina Aguilera, which was "shoved down our throats".

"I don't want to hear Christina Aguilera screaming through a stereo, but if I go to a shopping centre I'm surrounded by it."

Selzy said he had been contacted by Mr Wilkie and his mother through MySpace and at first thought it was a hoax because the idea of someone being charged for listening to his music seemed ludicrous.

"I thought it was bullshit at first," he said.

"Are cops going to show up at my shows and charge me with offensive behaviour?" he asked.