The term 'not classical' can be summarized by the crossword solution of 'POP'. POP music is a genre of popular music that originated in its modern form in the United States and United Kingdom during the mid-1950s. It generally consists of a mixture of commercial recordings of musical styles such as rock, R&B, soul, jazz, hip hop, reggae, electronic, and sometimes folk music. POP music often borrows elements from other styles such as rock, urban, dance, Latin, and country. POP music is usually more accessible and easier to listen to than classical music, and it is often characterized by short to medium-length songs, written in a basic format (often the verse-chorus structure), as well as the common employment of repeated choruses, melodic tunes, and catchy hooks.