At the height of the disco era, the birth of some of the best rock bands were occurring along with some of the best contributions from some of the early great rock bands. The late 70's early 80's is the golden age of rock music, in my opinion.
The Stones, Led Zeppelin, The Who, were all still killing it. The newcomers like Cheap Trick, The Cars, Van Halen, U2, etc were rising to prominence. Older bands took new directions with new members such as Journey, Genesis, and Yes. Some bands got new lineups and were just as good as before (AC/DC-almost as good).
All the while, The Bee Gees and disco groups were churning out pop hits, but bands like Queen and others were still making unique forms of excellent classic rock. Those days have a lot of good musical memories for me. I could go on all day about rock history.