Many elements of and reflections on tonality are to be found in Vaughan Williams's music: tonal centres are established and sustained, consonant triads are pervasive, and sonata form (a structure associated with tonality) is influential in the symphonies. But elements of the tonal system are also challenged: the diatonic scale is modified by modal alterations which affect the hierarchical relation of scale degrees, often consonant triads are not arranged according to the familiar patterns of functional harmony, and the closure of sonata form is compromised by the evasive epilogue ending of many movements and rotational structures. This music is not tonal or atonal, nor does it stand on any historical path between these two thoroughly theorised principles of pitch organisation. With no obvious single theoretical model at hand through which to explore Vaughan Williams's music, this analysis engages with Schenkerian principles, Neo-Riemannian theory, and the idea of sonata deformation, interpreting selected extracts from various works in detail. Elements of coherence and local unities are proposed, yet disruptions, ambiguities, subversions, and distancing frames all feature at different stages. These are a challenge to the specific principle of organisation in question; sometimes they also raise concerns for the engagement of theory with this repertoire in general. At such points, meta-theoretical issues arise, while the overall focus remains on the analytical understanding of Vaughan Williams's music.