Not so very long ago, Western music was seen as triumphant march from the primitive to the sophisticated. 'Old' modes gave way to 'new' keys, which in turn progressed from the simplicities of Monteverdi to the complexities of Wagner. To the great project of tonality, every major composer contributed his bit.
In fact, there never was such a project. Tonality was not deliberately constructed but just grew, like the giraffe's neck or the human brain, in response to an impersonal evolutionary force. There were, to be sure, periods when composers pursued a common ideal: ease and elegance in the eighteenth century, expressive power in the nineteenth. But their efforts were fitful and uncoordinated, and the results unpredictable. In any case, such ideals were simply the musical expression of the prevailing taste. They could hardly be expected to fit in with long-term tendencies unique to music.
Through every vagary of fashion, the tendency was towards a style of harmony both formally predominant and acoustically simple. It is the simplicity that strikes us in early tonality. There was very little in this unpretentious music to attract the ambitious composer. Its only evident merit was a certain rough vigour, perhaps combined, to the sixteenth-century ear, with an endearing folkiness. The enormous capacity for hierarchic organization had yet to be revealed. And here it should be remarked that harmonic hierarchy, in itself, was far from new to Western music. Primitive key relationships had already begun to appear in mid-fifteenthcentury polyphony,1 but the nearest that early sixteenth-century dance music came to them was the occasional II7/♯–V or I7\<–IV progression. It was only when the cadential hierarchies of the polyphonic style were combined with the harmonic simplicity of popular music that mature key systems became possible.
The merging of these very different traditions was a long and convoluted process. On the one hand, the great masters were loath to relinquish the subtleties of modal harmony; on the other, it took popular composers almost a century to develop even
1 Cf. Binchois's 'Adieu m'amour' (Ex. 6.1 on p. 67).