Sat front row at the symphony...

Every detail then how do you here the flutes and oboes along with the horn section that is 15feet in front of the back wall and projecting outward toward the conductor ?

Back in 1982 Richmond Colosseum, the summer home of the Chicago Symphony Orchestra. is incorrect the summer home for the CSO is Ravinia Festival in Highland Park Il, Glad you enjoyed the show they were probably in town for a few shows back then, But my cousin was the front of house sound tech for them there from 1976 thru 1988 then down at Symphony Center in Chicago,  Ravinia has a  wood dance floor stage with seating under a roofed pavilion which extends out to outdoor lawn seating with delay speakers placed all over the lawn. as i worked for them from 1976 thru 1999 while my father was the technical Director for the venue.

The following link gives the whole history of Ravinia Festival and the CSO's

history there.

https://en.wikipedia.org/wiki/Ravinia_Festival

Also  at the Chicago Symphony Hall the FOH mix position happens to be at the center rear of the balcony also if you look carefully above the musicians heads you will notice the condenser mic's placed there held in place with transparent fishline.