That's very gracious of you to admit! Obviously "the creator should dictate ..." part I just disagree with. Incidentally note that what you say is actually much stronger than the real situation - in the real world, copyright is time-limited and subject to exceptions ("fair uses"). It does not sound like you agree with these justifications - if you do, then my position can be phrased more palatably as "I think the class of fair uses is broader than you do".
About the specific moral question you pose:
> If a musican wants to do a performance once and not leave a record, why should he not?
Reversing the question is obviously, "If I want to record a performance I went to see, why should I not?". But I think this is easy to just answer directly. It is very hard to portray the musician who wants to prevent recording here sympathetically. Of course we can't appeal to the usual reasoning (that they're recording it themselves, and want to sell the recording) since you say they don't want it recorded at all. Maybe they want to sell an album, and they're playing the album in the show, and they want to keep recordings of those songs artificially scarce. So let's limit to the case where I record it for my personal use, and I'm not allowed to share it. Or I can sell the recording for the same price as the album, and I have to give it to the musician. What harm is there left for it to do?
The only remaining thing I can say as the musician is "I don't like it and I created the music so you can't have it". Sorry to say this, but this is the logic of a playground bully. Comparing the harm ("I don't like it and I will throw a tantrum if you record me") with the potential benefit ("I get to remember and relive this concert for the rest of my life") it is just a no-brainer to me.
