Despite an ever-expanding body of literature on Adès's engagement with the music of the past, his use of traditional formal models has attracted little critical comment. That which does exist privileges the relatively straightforward surface articulation of his musical forms over more nuanced accounts. In the case of Adès's sonata forms, this has had at least two consequences for our understanding of his music: first, that too strong an emphasis on syntactical groupings occludes what is happening discursively in the music; and second, that ‘textbook’ models are not the only formal tradition with which Adès's sonata forms engage. Rather, his sonatas bear traces of a rotational model that recalls the examples of Janáček and Sibelius. This article considers how Adès's sonata forms can be constituted not as neo-classical prefabrications but, a posteriori, as a practice that emerges across his career – from the Chamber Symphony and …but all shall be well to the Piano Quintet and Concerto for Piano and Orchestra – from an interaction between traditional syntactical groupings, thematic procedures and tonal plots.