Igor Engravor for Windows is available. What is it?
Igor Engraver is a music notation program, used for composing and arranging music. It can be likened to a typesetting program that works on music and music notation rather than words. As such, the problem of typesetting music is more complicated than typesetting text (which in itself is complicated). There are more issues to handle when notating music, as music has more dimensions than text.
It's been around for a long, long time, but this is a new release, ported to LispWorks from MCL. I'm glad it escaped bit-rot hell.