Thanks Noel. It may be different in the PC version.
I have song files with generic file names so I don't know what songs they are unless I go to File>Open Special>Open by Song Title and this will give me a title list of the songs of whatever folder is chosen. The heading in this window is SongPicker, which is why I called it that.

Yes, it should be obvious to click on the header, "Title" but when I do this the whole column highlights but nothing is sorted, and yes I tried right clicking = no response. And there's the message I mentioned about sort being disabled.

Maybe the guys who know what Mac version I'm using will also know this fundamental use case?

I used BIAB quite a bit in 2008 and after a 16 year break(!) I'm back with version Mac 2024.