Erdös numbers, Erdös-Bacon numbers, and Erdös-Bacon-Sabbath numbers are not uncommonly found on a CV these days. It's easy to find lists and online tools to discover low values for the first two, but not for the last.
Are there lists of musician-collaborators with the band Black Sabbath that were not themselves in the band -- corresponding to an Erdös number of 1, not 0? (Googling for that gets swamped by covers of their songs recorded by other bands.)
Or must one resort to individually contacting all of one's own musician-collaborators?