The title of the work, and those of its movements, were a late addition to the project, chosen after Messiaen made a list of ode au Saint-Laurent PDF work’s movements. Messiaen revised the work in 1990.
The demanding piano part includes several solo cadenzas. Introduced by trombones and tuba, this is the statue theme. According to Messiaen, it has the oppressive, terrible brutality of ancient Mexican monuments, and has always evoked dread. It is played in a slow tempo, pesante. It is introduced by two clarinets. This theme, the most important of all, is the love theme.
It appears in many different guises, from hushed strings in movement 6, to a full orchestral treatment in the climax of the finale. A simple chain of chords, used to produce opposing chords on the piano and crossing counterpoints in the orchestra. Modéré, un peu vif: A « curtain raiser » introducing the « statue theme » and the « flower theme », followed by the body of the movement, which superimposes two ostinato groups with rhythmic punctuations. A reprise of the « statue » theme closes the introduction. Modéré, lourd: After an atonal introduction, this movement is built on an alternation of a fast and passionate theme dominated by the trumpets, and a soft and gentle theme for the strings and ondes. Presque lent, rêveur: Three themes are stated: one starting with a solo clarinet, the second for low brass and strings, and the third a sinuous theme on the woodwinds.
The movement then develops and, later, overlaps the themes, with the addition of a new rhythm in the percussion. Bien modéré: Introduced by a scherzo for piccolo and bassoon, this movement is in nine sections, some of which recall and develop music heard earlier. A calm coda in A major brings it to a close. Vif, passionné avec joie: A frenetic dance whose main theme is a fast variant of the « statue theme ». For Messiaen, it represented the union of two lovers seen as a transformation on a cosmic scale. The dance is interrupted by a shattering piano cadenza before a brief orchestral coda. Très modéré, très tendre: The first full rendition of the « love » theme in the strings and ondes is accompanied by idealized birdsong played by the piano, and by other orchestral coloristic effects.
According to Messiaen, « The two lovers are enclosed in love’s sleep. Un peu vif, bien modéré: A completely atonal movement that is intended to invoke terror, with a predominant role for the percussion ensemble. Bien modéré: For Messiaen, the title can be considered in two ways. For the lovers, it is terrible: united by the love potion, they are trapped in a passion growing to the infinite. Musically, this is the work’s development section. Bien modéré: A theme is introduced by the woodwind. A five-part percussion ensemble introduces a rhythmic series that then sustains a set of superimposed variations on the woodwind theme.