"Rush" is one brand name for an Amyl Nitrate based product that comes under the general heading of "poppers"
Way, way, way, way way, Waaaa-aaay back when, they were a bus band that got booked into a bar where I was a regular. Back then, a lot of the bars were still shaped like an "H" because of the segregation laws. Nah, not that type of segregation, Single or stag male drinkers had to sit in one leg of the H and couples were limited to the other leg. The cross bar was the dance floor. The design went all the way back to pre-prohibition when the temperance unions were doing their "Killer Booze" propaganda schtick. Bands hated that configuration because it was impossible for the sound man to balance the sound so that it fed both sides equally. Plus which, the gain was almost always maxed out at 10+ due to background noise.
Not sure any more if they were the victims but a lot of the bands would suddenly "lose" one bank of speakers, making them play in monaural instead of stereo. Usually the culprit was a wire that had suddenly "snapped", usually because it had received some love from the blade of a Buck Knife. None of them ever figured out that they should stack all the speakers over on the "Ladies and Escorts" side and just balance that. The men's side didn't care; we were there to drink. Keeping the speakers at a distance would diminish the sound to a tolerable point. At one point it got so bad that the sound guy for that band about quit; he'd just manage to get the feed coax rewired and as fast as he turned his back, Darn, it broke again..............cheap wire...........................🤣. Pretty sure Rush was one of the targets for that kind of tough love; they got told and told to turn the volume down; they were either deaf or indifferent or stubborn; didn't much matter, class was in session and y'all gonna learn one way or another. Good Times, but i don't miss them. We all either grew up or died, Having alcohol for a mistress didn't make for longevity.
CopperNick