Azizi: you definitely need the Beginners Guide to Blind nicknames!
As I asked in a Sidmouth Festival Radio 2 folk quiz in c 1980:
who is the odd man out?
Blind Willie Walker
Blind Willy Purvis
Blind Willy Johnson.

When you can answer this, you're ready to rock.
(like all "odd man out" questions, there can be more than one right answer).