Tadd Hershorn’s biography of Norman Granz (see Doug’s Picks in the right-hand column) is full of instances of the mental 
acuity and toughness that helped see the promoter and record executive through countless challenging situations as he presented jazz and fought discrimination. He had a memory that was legendary among the musicians he worked with. Here is a story not in Hershorn’s book.
When I was a college student in Seattle in the 1950s, I became acquainted with Percy Heath, the bassist of the Modern Jazz Quartet. Following a Jazz At The Philharmonic Concert, Heath asked me to accompany him to a party at the home of a buddy from his days as a World War Two pilot in the Tuskegee Airmen. I met Heath and Ray Brown in the lobby of their hotel. As we were preparing to leave for the party, Granz walked by. Percy introduced me to him. We all chatted for perhaps 30 seconds, the impresario, two famous musicians and an anonymous student.
Flash forward. In the 1980s when I was living in San Francisco, I went to hear Dizzy Gillespie in the Venetian Room at the Fairmont Hotel. After his last set, I went backstage to greet Dizzy. As we talked, I noticed a figure seated at a table in the shadow of one of the ballroom curtains. Dizzy said, “Come over here and say hello to a friend of mine.” The friend, I saw, was Norman Granz, whom I had met just that once, in passing, in 1956. As Dizzy spoke my name, Granz said, “Oh, yes, we met in Seattle.”
For more on Granz, here’s a video that popped up on YouTube a few months ago. Described as a “taster,” it is apparently a promo for a documentary, but I have been able to learn no details about the full program.