YLEM is a fascinating composition, reflecting in musical form a literally universal concept. Beethoven was the first to be nicknamed the "universal composer", but Stockhausen here tosses his hat in the ring for that distinction. The available recordings are interesting documents, but I think a live performance would have a much greater impact, with the sounds moving outwards in space, and eventually out of sight. The think ideal situation would be where the musicians start at the center of the auditorium and move outwards in a circle, away from the audience in all directions. On the recordings, the glissandi of the Connection Players are a little bit too low in the mix for my tastes (as well as the shortwave radio events), but they do provide a nice added dimension to the sound ether, almost like shooting stars, or spaceships "taking off and landing" as Stockhausen characterizes them. Bernard Herrmann first used theremin tones to provide cosmic "atmosphere" to his film score for "The Day the Earth Stood Still", and the Connection glissandi at times reminds me a little bit of that feeling. Also, when the ensemble moves to the next higher pitch level at the second Big Bang, it's a bit like the universe has been reborn in a higher dimension. One wonders if Stockhausen was aware of current theories about the stacked nature of parallel universes...
I feel that it could be useful to have a discussion-forum on the music of Stockhausen. There are so many people from all over the world, young and old, learned and eager to get into contact with this musical world: musicologists, composers, musicians, music lovers; people who plan concerts - who write books or have to give lectures and so on. So there should be much stuff, many ideas that we can share. And when we have open questions, there may be people who studied just that and could give a hint or a stimulus.
A problem might be the English language, but i feel that is the only possibility that many people who are interested can participate. And we can exercise tolerance to mistakes!