Frank Zappa's widow GAIL has launched a battle to block a German music festival named after the late star.
She claims the Zappanale, organised by German Zappa fan club the Arf Society, and its logo infringes on trademarks.
Baffled members of the Arf Society claim the festival has taken place for 10 years, with the full knowledge of the Zappa family, reports the New York Post.
Zappa died in 1993, aged 52.