My jaw goes on the floor for that amazing riff and I can’t pick it back up again. No one has ever done anything like it.
He was a stunningly gifted composer, too. He “wrote” (exuded?) the first cut on the CTA album, “Introduction”. I can’t even count the number of key signature/timing signature changes in that masterpiece. In it, Kath foretold the unusual, ground-breaking nature of their band as a fusion of hard rock, jazz and mood.
Chicago still opens most of its shows these days with “Introduction.” It’s an amazing piece with all of the time and signature changes. I don’t think that Kath even knew how to read sheet music, but somehow they came up with that classic piece that does indeed “Introduce” what the band is all about.