A High Court judge is due to rule in a dispute between rock band Pink Floyd and record label EMI.
The band, whose Dark Side Of The Moon is one of the best-selling albums in music history, is challenging the legality of EMI's decision to make individual tracks from their albums available online.
The case also concerns how online royalties are to be calculated.
Robert Howe QC, appearing for the group, said earlier this week an agreement negotiated in the 1990s contained a clause that prohibited single track downloads without express consent.
It banned what was referred to as "unbundling" - the selling of record tracks, either physically or online - "other than in their original configuration".
EMI argued that the prohibition "applies only to the physical product and doesn't apply online".
Mr Howe told Sir Andrew Morritt, Chancellor of the High Court, the band was well known for producing "seamless" pieces of music on albums and "wanted to retain artistic control".
The legal dispute is focused on an agreement reached several years before the download market was launched in the UK by Apple through the iTunes Music Store in 2004.
Mr Howe said both parties had been faced at the time the agreement was drawn up with a whole new world of potential exploitation of music "and quite simply they didn't know how that would work out".
He said it would have been "a very odd result" if members of Pink Floyd were able to control exactly how their music was sold as a physical product but there was "a free-for-all with no limitation on online distribution".
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