I just completed the 1981 list, once again only drawn from UK charted singles. Already it is easy to see the crap production creeping in, some bands reaching their twilight others at a peak from which they would collapse never to recover.
I still managed a good long list but it was harder picking over the dross to unearth the nuggets.
Maybe '83 will see some improvement, but I suspect after '84 it will be extraordinarily slim pickings for my imaginary covers band.
Popular music has always followed these patterns. Brief spikes when even the top 20 might contain a half dozen decent tunes, followed by long years of drought.
I suppose there is a reaction from musicians to the dull, conformity of the times, so they shake things up. Then the establishment get hold of what they're doing and gradually wring the life from it in pursuit of sales. Then musicians rebel and the whole thing repeats.