The simplest — and working — solution is, to integrate a blog system into Muse, and let your customer edit the blog entries.
All other solution are not really viable.
Two recommendation, which differ especially in the way, these blogs are hosted:
Thanks for this Günter,
I've used Wordpress so there is some familiarity with the blog widgets you've suggested. I'm assuming the client would be able to delete an expired post (gig) and duplicate the last post to create a knew one making the necessary edits?
The client has asked for something like this https://parishpub.co.uk/gigs which to me looks like is content managed by the designer, as the individual events are just single images.
I'm assuming the client would be able to delete an expired post (gig)
Depending on where it's hosted and whether or not you are allowed to use/ install plug-ins, you could let them even auto-expire.
duplicate the last post to create a knew one making the necessary edits?
That's what the WP-native "Writing Helper" is for, anyway, either via the "Copy a Post" command in the dashboard sidebar or below the post editor. Depending on what specifically your client needs/ wants and also persuant to whether or not you are allowed to, you might consider a custom post template. This would make this 100% foolproof and would also have the advantage of allowing custom formatting, tags etc. beyond the currently active theme.