In its final form, Op. 54’s first movement engenders an analytical paradox. In its original incarnation, it realised Schumann’s ambition, first voiced in 1836, to combine ‘the Allegro-Adagio-Rondo sequence in a single movement’, thereby instantiating the compression of the genre’s movement cycle into its first-movement form. To an extent, the full Concerto of 1845 undoes this ambition: those aspects of the Phantasie, which invoke the features of a slow movement and finale, recede into the first movement once the second movement is underway. The first movement is nevertheless distinctive for its rejection of both the classical and virtuoso sonata-ritornello form in favour of a unitary, symphonic sonata form. This chapter examines the Phantasie’s form and the processes from which it is constructed, exploring the implications of its inclusion within Op. 54 for the work’s three-movement design and clarifying its multiple but largely neglected debts to the virtuoso repertoire. Schumann retains the virtuoso concerto’s stylistic hallmarks, but rehouses them in a new formal context and makes them responsible to processes of thematic transformation and development.