The title, Pli selon pli, is taken from a Stéphane Mallarmé poem which is not used directly in the composition. Translated as ‘fold by fold’ or ''fold according to fold,' the piece, according to Boulez, ‘indicates the meaning and direction of the work. In this poem the author thus describes the way in which the dissolving mist gradually reveals the stones of the city of Bruges. In the same way, as the five pieces unfold, they reveal, fold by fold, a portrait of Mallarmé.’
The recording here by the BBC Symphony Orchestra under the composer’s direction is the first complete recording of the work, distributed by CBS in 1969-70. Pli selon pli consists of five movements with the outer two, Don and Tombeau, serving as full orchestral bookends to the three smaller ensemble Improvisation sur Mallarmé. Don and Tombeau have a form independent of the Mallarmé sonnets and whose opposition evokes a birth-death polarity. For the text of Tombeau, Mallarmé reflects on the death of fellow poet Verlaine just as Boulez was also reflecting on the death of Prince Max Egon.