It pains me to admit this, but I am having problems analyzing Charles Ives' songs. I get the quotation stuff, and especially dig Peter Burkholder's extensive list of different types/methods of quoting and paraphrasing. I also understand Ives' use of various scales (esp. the whole tone scale) and the blatant polytonal effects of some songs. But many of Ives' chords do not fit neatly into a category of polychord, pc-set, extended tertian harmony, or other standard 20th century harmonic thingee. As an example, in "The Cage," almost all of the chords are quartal, with 3 quintal chords and 3 other chords. One occurs at the end of the introduction, one occurs at the first rhythmic break in the vocal part, and one occurs at the climax.
The first such chord could be a polychord of D minor and F#-7, except it overlaps too much to have an effective splitting of chord types. It could be a secundal chord, except it is spread very open, without that clustered feel that most secundal chords have.
Moving to the climax, this chord is essentially a complete whole tone chord (C#,D#,F,G,A,B) plus C. The C is not isolated in the voicing, and again the overlapping prevents a confident reading of an F7/G+ polychord. Looking at either chord makes it seem like there should be some symmetry or intervallic relationships at work, but I can't see them. Sometimes a dissonant chord can just be a dissonant chord. Perhaps not being a quartal chord is enough description and function.