Complex sentence: She premiered John Tavener's dramatic cantata "The Whale" at a Proms concert on 1 August 1969, conducted by David Atherton, with soloist Raimund Herincx, and Alvar Lidell and the composer playing pipe and hammond organs.
Split into simpler sentences: She premiered John Tavener's dramatic cantata "The Whale" at a Proms concert on 1 August 1969, conducted by David Atherton. Also appearing was barritone Raimund Herincx, narrator Alvar Lidell, and the composer playing pipe and hammond organs.