How many are there genres of music in the world?

It is difficult to say exactly, as there are many ways to categorize music. Some sources estimate there are hundreds of genres, while others say there are only a few dozen. Some common genres of music include rock, pop, hip hop, R&B, country, electronic, and classical. Each of these genres can be further divided into subgenres, such as heavy metal, punk, folk rock, alternative rock, and so on.