I understand the concept of a figure of speech, why use a figure of speech when a simple "i have never heard of" would be true and more appropriate.

I'll bet you're the life of the party...:woohoo:

Depends whose party.
Doesn't change the fact that the guy was not unknown in the UK and Western Europe, although not "famous", as the music scene was evolving in the 60's. Maybe unknown in the USA at the time but there's a whole world outside of that.
Happy Christmas to all Peter Green and "early years" ledgies.