Apple Corps Ltd, the Beatles' record company and guardian of the band's musical heritage and business interests, is suing Apple Computer Inc, claiming the company violated a 1991 agreement by entering the music business with its iTunes online music store.
The case will be heard on Wednesday by Judge Martin Mann, who said during pre-trial hearings that he was the owner of an iPod digital music player, which is used with the iTunes music store.
At the centre of the case is a 1991 pact that ended a long-running trademark fight between the two Apples in which each entered into a "field of use" agreement over the trademark.
Apple Computer said in a statement that "unfortunately, Apple and Apple Corps now have differing interpretations of this agreement and will need to ask a court to resolve this dispute".
Apple Corps - founded in 1968 and owned by surviving Beatles Paul McCartney and Ringo Starr, the widow of John Lennon and the estate of George Harrison - is seeking both an injunction to enforce the 1991 agreement and monetary damages for the alleged contract breach.
The computer company's logo is an apple with a bite out of the side; the record company is represented by a perfect, shiny green Granny Smith apple.
Apple Computer had asked to have the case heard in California, where it is based, but Mann rejected that application in 2004 and ordered the case be heard at the Royal Courts of Justice in central London.
Apple Computer was formed in 1976, when two college dropouts - Steve Jobs and Steve Wozniak - filed partnership papers on April Fools' Day.
Steve Jobs - seen with an iPod -
is co-founder of Apple Computer
Their goal was to build and sell personal computers, and their first product was a build-it-yourself computer kit.
In 1984, the Apple Macintosh was introduced. Its ubiquitous iPods first came out in October 2001, and have popularised the notion of music and video on the go.
The iTunes music store first opened for business in the United States in April 2003; it is now available across Europe, in Australia, Japan and Canada.
About 3 million songs are downloaded everyday from the service. In the US, a song costs 99 cents.
Beatles' songs have not been licensed for downloading.