Relations between St Marys Band Club and St Marys District Band have hit a sour note.
The club has spoken out about its strained relationship with former members of its brass band, who have re-formed in Penrith.
St Marys District Brass Band was formed in 1882 and set up St Marys Band Club in 1956.
The club sponsored the band until the relationship broke down last year.
The district band demanded through its lawyers that the 21,000 member band club change its name and give back trophies and the land.
"We were mortified and couldn't believe they could do such a thing," St Marys Band Club chief executive Marlene Shipley told the Star.
"We will be fighting this for the club and community. It's disappointing because it's expensive and we shouldn't have to go through [with it]."
But St Marys District Band has accused the club of public mud-slinging.
"The withholding of critical information, and the baffling insistence on viewing a club member's worth by post code contributed to the band's decision to sever ties with the club," band music director Ben Crocker said.
The club is fighting back and has asked the band to return instruments and change its name.
"The instruments were paid for by club members," Mrs Shipley said. "We don't have any issues of another brass band being in the community. But we want them to cease using the name. We will continue to have a brass band in the future and are seeking expressions of interest."