The origins of the case can be found in what, to some, is a similarity between ‘Stairway to Heaven’ and ‘Taurus’, an instrumental piece from the 1968 debut album of the band Spirit. The two bands shared the bill at several concerts at the end of 1968 and throughout 1969.

Hugely valuable IP

Randy California, the Spirit guitarist who composed 'Taurus', died in 1997. Francis Alexander Malofiy, representing the late musician’s trust, filed the suit in May 2014 in an apparent bid for a slice of the estimated $560m the song has made since it was released.

Limited recollection

Robert Plant (pictured), Jimmy Page and John Paul Jones were each deposed separately over the past month as part of pre-trial discovery and deny any pilfering, though Mr Malofiy has pointed out that band members previously said their memories of the period were hazy at best. According to a filing by Mr Malofiy, all said during the deposition that they had no idea what their finances or earnings were with Led Zeppelin. He now wants the trial date to be moved from May to July to give him more time to process the masses of information he's gotten in discovery, which includes 40,000 pages of financial records.

Preliminary recordings

The case could make for good listening should it come to trial, as Led Zeppelin’s legal team says preliminary recordings prepared in the creation of ‘Stairway to Heaven’ have been located in response to discovery requests. The two sides are also still battling over whether the defendants should turn over a so-called multi-track version of the song, which would enable the different elements to be isolated. Sources: Bloomberg; Bloomberg (2)