Hi all, thank you again for the support.
First, to the couple of posters apparently fixed on the idea I'm trying to hide gender: I wasn't. There is no rarity in using a pronoun: "they" is a perfectly usual terms for one's spouse. DW or DH isn't, but that seems to pass without comment! Anyway, irrelevant, but I would respectfully add that the posts do little to dissipate the anti-man perception that some of you indicted exists (or is perceived to exist) in some quarters on mumsnet. :-)
Second, on hobby vs work. While they are paid, they are not my main source of income: lecturing in music is, but obviously music is not merely a theoretical enterprise, so staying playing and current is mandatory to be an effective practitioner. So, yes, it's not equivalent to the boozer, or even Saturday football.
Third, on time parity. We both spend every evening and every weekend with our daughter, doing homework and having fun. The only time I don't is one half-evening a week I work late, and one half-evening rehearsing, plus of course the gigs, max 24 per year.
Forth, on chore parity. It's a reasonable, but limited criticism. To be sure, I do do a large fraction of my fair share(!)––tidying, school runs, driving, homework, bins, shopping, hanging laundry out, logistics (bills etc), DIY/'man' stuff (sorry!). However, she does a lot more cooking than me. Not all. But a lot more. And more laundry too. But I still don't think that justifies her behaviour in this regard.
Fifth, on my parents. I think she likes them (and there is nothing not to like about them, they are devoted and would do anything for us) although will be rude about them if she wants to hurt my feelings in an argument (but I'm not counting things said in anger).
It is, in my view, a combination of two factors: Pathological Parity (i.e. if she feels guilty about using childcare for her nights, and so doesn't, then I have to feel bad too: I don't, and use it, so she gets angry) and Control (when things stick to the predicable, even-keeled routine she's fine: whenever anything different happens––literally anything, like a night out––it's somehow 'out of her control' and the challenge results in more anger).
Now, that's some pretty cheep armchair psychology, but it feels not too far from the mark.