For some time I have been interested in the use of different types of music within a single composition. In some respects this goes back to the prima and seconda prattica of Monteverdi, the contrast between polyphonic and homophonic writing in Handel's oratorios, or even the French, German and Italian elements in Bach's keyboard music. But what I am concerned with emerges only in the later nineteenth century and gains stature through the works of Charles Ives. It often involves types of popular music at a time when the harmonic language of composers had become too advanced to incorporate a folksong as effortlessly as in Schubert or Brahms. And it has something to do with the impact of African American musical practices as they filter through popular songs and dance music in both Europe and America. I am trying to look at the beginnings of the process rather than its wider diffusion since the 1960s, which has gone on well into the twenty-first century. Compositions involving different musical styles are easily misunderstood, as reactions to Ives have shown. However, it may be time to acknowledge that techniques for the manipulation of style can be as crucial as other elements in composition and there may be something to learn from studying them in relative isolation.

Modulation is traditionally associated with key, but the notion has been expanded to cover the metrical ingenuities of Elliott Carter – hence metrical modulation. Fifty years earlier Ives employed a technique of working with various types of music which can justifiably be called ‘style modulation’. That is, the use of different musical styles within a single work in a way which is as calculated as any other element of control. The contrast created is sometimes the result of incorporating aspects of popular music, especially the derivatives of African American traditions.

When this happens there is a conflict of cultures behind that of musical types – a familiar situation in Ives where the private world of his dissonant music rubs shoulders with hymns, marches or popular songs. But the result has needed time for it to be recognised as Ives’s personal way of ordering his compositional materials.