What it Popular music?

The term popular music, has changed its definition over the years, for example the word 'popularis' meaning belonging to the people, to it changing in the 16th century meaning 'low/common', to its 18th century definition of being 'widely favoured', In my opinion I think people tend to classify 'popular/pop music' as a genre and having this idea that pop music has to have a certain sound, and in recent times concentrating on commercial music reality shows and exclusively labelling that music as 'pop'. I believe this is not the case as songs from many genres become 'popular' not forgetting music which is 'popular' in other genres in other parts of the world or successful 'popular' music in specialist niche markets, that would not be commercially successful in other parts of the world or in the mainstream market but is 'popular' in their own market, and considered popular by its listeners.