Most scholarship on what Arnold Whittall has called the ‘moderate mainstream’ of musical composition since 1900 has tended either to presume that its techniques are conservative, and so to allow it no part in the narrative of musical modernism, or on the contrary to insist that it is modernist, but without precisely explaining how modernist aesthetics are to be rewritten in order to accommodate the new style. While retaining a focus on the radical core of the modernist event, but without reducing all artistic production to a binary opposition of radical and conservative, this chapter argues for an aesthetic, intellectual, and political middleground for ‘reactive’ music, between the poles of a ‘faithful’ modernism which confidently asserts the possibility of a new, post-tonal artistic configuration, and an ‘obscure’ modernism which utterly rejects the abandonment of tonality and willingly submits to the aesthetic blandishments of the pure commodity.