Modern popular music
When people talk about popular music they may refer to completely different musical genres that vary greatly. Moreover, the term "pop" music is still sometimes used to denote the more general variety of musical genres, and not only is what now known as pop music (the one that's opposed to rock, hip-hop etc.). That's why abbreviating the term popular music is not correct as pop music is a lot narrower definition. The characteristic feature of popular music is that due to its popularity its works are primarily distributed on a commercial basis and the popularity (and thus the talent) of musicians and singers is quite often measured by the amount of the money they make by selling their records. This very factor distinguishes popular music from the classical one which was originally created for the elite and the "upper" strata of the society, on the one hand, and folk music (which is today more often called "traditional music"), whose creators did not require any money reward. Popular music is music of different genres that are available for the general public and distributed on a commercial basis. Among them are such styles as pop music itself (the "traditional" pop music), rock'n'roll (and later its numerous variations), rhythm and blues, disco, reggae, hip hop and many others. Some of these styles of music gave birth to further sub-styles as people's tastes changed or as they became available for wider audiences. The more people listen to a particular music genre, the more variations it has or will acquire sooner or later.