Hello, Elwood.
Have you found this thread yet:
viewtopic.php?f=7&t=31I wish I'd known about it before taking up my recent self-imposed task of listening to all of Polly's output over which she had some creative influence. I'd think I had it all sorted and ordered, and then discover something else.
What that very helpful list doesn't do is describe exactly what the degree of collaboration is in any given case, or the production circumstances of a particular non-album track. For instance, 'Nickel Under the Foot' might be considered a cover, as it's Polly's version of a song from a 1937 musical contributed to the soundtrack of a film about the
making of said musical - which is quite complicated!