Mahler used heterophony (the "indistinct unison") as far back as the first published version of the First Symphony and the original (MS) version of the Second, hence from the mid-1890s on. It usually takes the form of overlaying ornaments or momentary doublings in contrasting timbres on a relatively continuous melodic line; occasionally the main melodic line is itself fragmented as well. Locally it serves to highlight specific details of pitch or rhythmic contour in the line; it also has a long-range role. Recurring material in sectional forms (i.e., the rondo-like third movement of the Second) is often recomposed upon returning, with enriched heterophony as well as in more complex textures. The issue of Eastern influence is another matter, however, since by the time of Mahler's reported encounters (confirmed or not) with either written transcriptions or recordings of Asian music, heterophony both combined with and independent of melodic fragmentation had already become an essential part of his orchestral language. I discussed this matter at some length in an undergradate Honors thesis on the structural role of instrumental color in the first 4 symphonies of Mahler written as far back as 1961. Should have published some of it.... Joel [log in to unmask] <mailto:[log in to unmask]>