In many ways, the arts in the seventeenth century were shaped by the same aesthetic principles that had held sway during the sixteenth: the Humanist belief that a work of art had the ability, through imitation, to portray psychological, moral and other realities, and the power, through rhetorical means, to make those realities present to others. Writers from antiquity to the present have recognised these dual goals as common to the ‘sister arts’, by which they usually mean painting and poetry. The phrase connotes a certain rivalry that was based on Horace’s famous dictum ut pictura poesis – as is painting so is poetry – a comparison much discussed during the Renaissance, with the result that painting acquired the status of a liberal art in the sixteenth century and was deemed to deserve serious consideration equal to that given to poetry. But the beliefs and goals that were shared by the sister arts of painting and poetry also propelled developments in architecture, sculpture, theatre and music in the Renaissance and Baroque periods. In fact, early-modern writers on music, particularly those who relied on Plato and Aristotle for their understanding of the educational ideals of Greek culture, stressed the inseparability of music from poetry. For our purposes, then, music was indeed one of the sister arts and this chapter will suggest ways in which it participated, both in theory and in practice, in the various aesthetic dialogues that characterise the age.