Eric Goldberg contributes an informative note on Kupferman's music:

>Kupferman utilized mostly atonal devices in his music.  He created
>a series of works that are based on what he called his "Infinity tone
>row".  That is why many of his pieces are called Infinity No. xx.
>
>G-F-Ab-Cb-Bb-D-F#-E_C-Eb_A-C#
>
>He handled the row somewhat differently from most composers in that he
>utilized the third pitch of the row as the pivot rather than the first
>note.  I cannot vouch that he was consistent in this technique.
>
>He also used scales such as the symetric scale which alternates whole
>and half tones:
>
>C-Db-Eb-E-F#-G-A-Bb-C

Also known as the octotonic scale.  Stravinsky used it too.

I have a slightly different take on Kupferman than Eric does.  Yes,
he used dodecaphony, but it wasn't necessarily "atonal" dodecaphony.
"Tonal - Atonal" is a spectrum rather than two separate paint chips,
anyway.  I usually found Kupferman's music far closer to the tonal
side of things.  Furthermore, he often seemed to mix avant-garde (or
Schoenbergian) procedures with traditional ones.  I've heard pieces I
would describe as modal, with dissonance, and atonal with consonance
thrown in.  He never seemed to me locked into one technique or another.
He almost always seemed to search for some sort of synthesis in
superficially "incompatible" styles.

Above all, there really is no Kupferman "sound," something that identifies
Kupferman immediately to the ear.  He explored so many things, he passed
up that trait.  It makes it hard to describe the music, for one thing,
and you really have to be willing to immerse yourself in a large body
of work (even a small part of it is a lot of music) before you get some
sort of fix on him.  The advantage to me, however, is that I know many
Kupferman pieces that don't sound like each other.  He found many ways
to write good stuff.

Steve Schwartz