Malone
Many thanks - I have got it now, although I had to look it up.
I had assumed that as there are "bars" in music, then Barmen (men who make bars? - composers) might be right. But it is straightforward and explains the changes , as you say.
Thanks to your hint, I dont have to worry whether "Barmaids" might be included.
In a strange twist, my earlier posting mentioned the setter's name. I had mis-remembered this and my error hinted at the theme.