Conversation so far:
What did the artwork for At Fillmore East consist of?
The cover of At Fillmore East is a photograph of the band in an alley waiting with their gear to go onstage.
Was there anyone in particular that played a bigger part in the artwork idea of the At Fillmore East album art?

Question: Who was the photographer?
Self-contained rewrite: Who was the photographer of the At Fillmore East cover art image?