The brother and sister act found themselves competing with a hum of general conversation for much of their set, as well as a loud admirer who peppered their famously less-is-more arrangements with declarations of love for the female Stone.

The crowd noise persisted until Julia paused between songs to invite chatty concert-goers to take it outside. 

‘‘I never do this,’’ she said. ‘‘But I know there are people here who really want to listen.’’

The pair were performing at Anita’s Theatre as part of a national tour. 

Fans including Nichola Gabriella Pereira have since taken to their Facebook page to praise the performance and say sorry.

‘‘I want to apologise on behalf of the idiots that screamed out s*** and talked over your set,’’ Ms Pereira wrote. 

‘‘I’ll never understand people that pay money to hear live music and then talk through it all.’’

Another in the crowd, Michael St John, said he lost patience with some noisy concert-goers and told to them ‘‘to shut up’’.

‘‘[A companion] on leaving made the comment that this place should be renamed ‘‘Thirrude!’’

Others said they were ‘‘embarrassed’’.

‘‘We promise that the rudeness of crowd was not a reflection of the entire audience or the south coast population,’’ wrote Courtenay Turner. ‘‘We’re so sorry if you felt uncomfortable or unappreciated.’’

The Stone’s manager Tim Manton told the Mercury the crowd reaction had left the duo ‘‘very upset’’. 

The concert was a big-name coup for the historic theatre, which was sold to Brusnik Enterprises in November 2013 for $1.4 million.

The company has since invested in new sound and lighting equipment, entered into a booking arrangement with Oxford Art Factory and stepped up the venue’s musical offerings.

Brusnik Enterprises director Nik Josifovski said the low volume of Wednesday’s show — compared to a rock concert — may have contributed to the effect of crowd noise.

‘‘No one can normally be heard over a rock act. I think the lower decibel level was why people were maybe able to be heard,’’ he said.

‘‘Ninety-nine per cent of people I’m sure would have enjoyed the music. It only takes one or two idiots to spoil it.’’