For a time in the mid 1970s you were not taking audio seriously if you were not also releasing your albums in quad. It acquired status. The serious audiophile ensconced in a stores’ listening booth, stroked their chin and confirmed the superiority of the sound. I’ve got, by accident, some quad albums, including Chicago at Carnegie Hall. Despite claims to the contrary, now and then, I can't tell any difference. Admittedly I’ve always found those blokes (it’s always blokes) in the listening booths to be over precious. I have never been an audiophile wanting to listen to a perfect recording of Dark Side Of The Moon. This has always surprised some people. I’m a big record collector, don’t I want as good an audio experience as possible? Well I do, but my standards are rock n roll. I don't care to an extent about distressed records or mint records. Skips, crackles and scratches, to me, are all part of the listening experience. The fussy attitude to noise on records, is what led us into the arms of CD’s and that is a soulless experience which current generations are sensibly rejecting. It feels like rock n roll is a rough and ready experience, at odds with the very idea of pristine sound. So there is nothing wrong with the clicks and scratches. Likewise the introduction of quadraphonic seemed… well, irrelevant. If it had blown your mind with a whole new sound dimension, I’m sure I’d have been interested. But it didn’t. Quadraphonic had a long and difficult birth, starting in the 1950s. In 1967 Pink Floyd incorporated quad into their live sound, for a fully immersive experience. They released a quad version of Dark Side. It wasn’t better than the stereo. The whole process of Quadraphonic recording is beyond my simple brain but I understand there are different ways to do it. But that in itself is part of the problem. The records were released but insufficient numbers of people cared. Some albums sold well, like DSOTM and Bridge Over Troubled Water. A good seller was Switched On Bach. It was surprisingly persistent, being remixed into the late 80s on CD. I think the truth is that fans were big fans and loyal to the concept. Enough audiophiles were around to sustain it. But to most people it wasn’t needed and eventually interest faded away, leaving lots of quad albums on the market, occasionally collectible, but more usually not.