Pop music is the genre of popular music that produces the most hits. A hit is a song that sells many copies, and the latest hits are listed every week on the charts. To get on the charts, a song must be released as a single, although most singles are also released on an album. Songs that become hits almost always share certain features that are sometimes called the pop-music formula. They have a good rhythm, a catchy melody, and are easy to remember and sing along to. They usually have a chor...