It was relatively easy to trace the continued evolution of the three-voice cantilena-style motets in chapter 9, since their basic texture stays the same. Things are more complex when we turn to the motet-style motet and developments in four-voice writing in mid-century. The various oppositions and threads of development (English and continental, three- and four-voice, with and without cantus firmus, with and without isorhythm) become tangled. I have chosen to divide the repertory into works with tenor cantus firmus and freely composed works for more than three voices. In this chapter I focus on works of the first group, which trace the strongest line of descent from the great English and French traditions of isorhythmic motet composition. I begin with the motets closest to the Q15 repertory: the four-voice isorhythmic motets in which the top voices are in the same range (Table 10.1). I go on to consider four-voice works in which the upper voices are not in the same range: here I consider both English and continental works (Table 10.2). I turn then to a new non-isorhythmic subgenre, the three-voice tenor motet (Table 10.3). I end with the first major four-voice cantus firmus work without isorhythm, the anonymous English Missa Caput. Although I concentrate on works found in the earlier Trent Codices (87, 92, 93 and 90) and Modena X.1.11, I also include other contemporary pieces, in order to provide a comprehensive look at the surviving examples of these subgenres.