Attendees of the recently held Silverchair concert in Darwin are angry over the behavior of the band's lead singer.

The Northern Territory News reported that Silverchair's vocalist Daniel Johns swore during the BassinTheGrass concert, calling people in the crowd "sluts" and "whores".

Johns liberally said the word "c***" which offended women from the audience.

"It's so sad that this dude can be such a tosser," a concertgoer said, adding that Johns should "stick to singing with no talk in between".

According to a tradie who was also at the concert, the swearing was offensive.

"It didn't worry me - but if I had had a daughter in the crowd, I would have wanted to get on stage and smack him in the head," he said.

"It was an all-age event and he shouldn't have done it."

On the contrary, Northern Territory News Confidential editor Daniel Bourchier said that only a few people were offended with Johns's foul language.

"Johns swore every time he talked. But it was a rock concert, not a tea party," he said.

But Bourchier said that people were taken aback when a song about underage sex was performed by the artist.

"He's an old man and it seemed a bit sleazy singing about kids having sex."

"We don't make on-the-record comments about what our artists say on stage," said Bernadette Faddoul, publicity officer of Silverchair.

BassinTheGrass is an all-day music festival held and organised every year by the Northern Territory Government.