In the late 1960's or early 70's in Detroit, two FM radio Stations simulcasted the same stereo music to produce four track sound over sound surround sound broadcast, that required listeners to have two stereo FM receivers, [four speaker set up on in each corner of a square and the listeners sat in the middle] one each on one of the different stations. I recall it took place on a summer Saturday and it was really nice out; we sat up our stuff in the back yard to listen, and it was really cool to hear the broadcast; I work as an intern [go for] at a small recording studio back then and knew what true four and eight track music sounded like when played back in a surround sound type environment
What was those two station who took part and in what year. I really do believe one station was WABX but not sure of the other...please help my failing memory.
Thanks for any input