I didn't know Bob but I was fortunate enough to work with another legend of live sound: Tommy Linthicum.

The sound company he started with his highschool friend (National Sound) ended up doing the first 11 world tours for Rush. He pioneered "flying" PA speakers above the stage in the 1970's. Before that they were commonly just stacked on the front/sides of the stage. Later, National Sound merged with another company to form National Events, which did sound/light/staging for almost all of the major concerts and political rallies on the national mall in DC for several decades.

I made a tribute video after his death in 2007: https://kevinloch.com/tommy/tommytribute-highres.avi