The classification of music into categories is often expressed as styles or genres. Arguably the two words are interchangeable and is based upon a set of musical characteristics that are recognised as belonging to a named category; such as Blues or Jazz etc.
However, it is a thankless task and categorisation is often never clear cut. When there are as many categories as there are songs then the object of classification has almost been defeated; the purpose of which is to simplify the world of music.
Still, we continue with categories described as styles or genres. In conversation, reference to a style or genre as least gives an idea of what is being talked about; as the word no doubt conjures up a set of characteristics that are considering defining.
In musical terms, styles and genres are like languages. Their evolution is often complex and happens over an extended period of time. Often the language is learned through exposure and the passing on of characteristics; as it doesn’t require the conservatory to be educated in these things.
There is no question that exposure to a style is paramount to learning about a style with a view to playing it, improvising with it etc. One can learn through imitation just as a young child will learn about language by copying their parent’s speech and language; which is more important than learning about the alphabet or the rules of grammar.
20th century popular music styles: