On going through his papers , Loriod discovered that , in the last months of his life , he had been composing a concerto for four musicians he felt particularly grateful to , namely herself , the cellist Mstislav Rostropovich , the oboist Heinz Holliger and the flautist Catherine Cantin ( hence the title Concert à quatre ) .
Messiaen had also been composing a concerto for four musicians he felt particularly grateful to : his wife Loriod , the cellist Mstislav Rostropovich , the oboist Heinz Holliger and the flautist Catherine Cantin .