Rock band Pink Floyd launched a High Court action against EMI yesterday in a dispute over the calculation of online royalty payments and marketing of their music.
The band, whose Dark Side Of The Moon is one of the best-selling albums in music history, is seeking a ruling on two key issues.
Robert Howe QC, appearing for the group, said they wanted to "know where they stand as a matter of contract".
The case concerns how online royalties are to be calculated.
Mr Howe said it also concerned EMI's "entitlement to sell individual tracks, or indeed any tracks, otherwise than in the original configuration of the Pink Floyd albums".
He argued that a contractual clause "expressly prohibited" what was referred to as "unbundling" - the selling of tracks, either physically or online, "other than in their original configuration".
Mr Howe said EMI was arguing that the prohibition "applies only to the physical product and doesn't apply online".
But that "makes no commercial sense" and was contradicted by the conditions used in the agreement with EMI, argued Mr Howe.
Pink Floyd signed with EMI in 1967 and became one of its most lucrative signings, their back catalogue being outsold only by that of the Beatles.
Yesterday's hearing was the start of what is expected to be a lengthy legal battle.
Applying for a summary judgment against EMI, Mr Howe said the company had been permitting individual tracks from Pink Floyd albums to be downloaded on their own.
This went against an agreement negotiated in 1998-1999 which contained a clause which effectively prevented the exploitation of the band's music as single track downloads without express consent.
The band was well known for producing "seamless" pieces of music on albums and was clearly what they wanted to achieve.
It was understandable they "wanted to retain artistic control".
Mr Howe said it would have been "a very odd result" if they were able to control exactly how their music sold in its physical form but there was "a free-for-all with no limitation on online distribution".
Mr Howe argued the definition of "record" embodied not only the physical album, but also included any new formats, and was broad enough to include the new single digital download.
"Prohibition applies equally to the digital product as it would to the physical product, as one would expect from the commercial purpose of the clause - there would be a digital free-for-all otherwise."
Elizabeth Jones QC, appearing for EMI, disagreed and said the word record "plainly applies to the physical thing - there is nothing to suggest it applies to online distribution".
At the time the agreement was drawn up in 1999, iTunes downloads did not exist, being introduced in 2004.
Ms Jones said: "There is nothing in the agreement suggesting the commercial intent was one way or the other, if you look at the clauses in the context of the whole agreement."
Sir Andrew Morritt, Chancellor of the High Court, said he would give his ruling on Thursday.Reuse content