The term 'A LOT OF TOP 40 MUSIC' can be summarized by two three-letter words: RAP and POP. RAP is a genre of music that originated in the United States in the 1970s and is characterized by its use of rhyming lyrics and spoken word. POP music, on the other hand, is a genre of popular music that originated in the 1950s and is characterized by its catchy melodies and accessible lyrics. Both genres have been staples of the Top 40 music charts for decades.