Popular music can do either of those things, but popular music that stays well known and popular for years and years are those songs and albums that give the people something they have never seen before. Think of some of your favorite artists from the past: Queen, David Bowie, Elton John, etc. They all brought to the table what no one else was able to do and I think those leaps of faith speak for themselves. They are what keep the development of music going and pushing into the future instead of recycling the same old beats until you're beating a dead horse.
The answer is the last one! Like any other art everything is subjective so anything can be a good subject
By showing objects on the table from various vantage points at the same time.