A landmark ruling is expected next week that could have major implications for the ownership of music copyright.
The plaintiffs, former members of 1980s pop group Spandau Ballet, are claiming hundreds of thousands of pounds in royalties from songwriter Gary Kemp.
They claim that because they assisted in the rehearsing of songs and performed on the recording they were part of the creative process and added something unique to the songs.
"If the plaintiffs succeed, the songwriting process will be stifled. Songwriters will not be able to rehearse their songs with others for fear of litigation. There is a vital difference between the creation and arrangement/performance of a song. Although an arrangement may be dramatic the song remains unchanged," says Charles Russell partner John Sykes, who is acting for Gary Kemp and his company Reformation Publishing.
Irving David, senior partner at David Wyman Solicitors who is acting for the plaintiffs - singer Tony Hadley, drummer John Keeble and saxophonist Steve Norman - says: "The implications are not just for session musicians but more importantly to all non-writing members of bands who assist in the creative process by rehearsing songs before they are recorded."