Songs getting simpler and more repetitive over the last 40 years - Science and art. Over time the lyrics have become more emotional and personal.
Use of emotionally positive and negative words increased in rap songs, while the use of emotionally negative lyrics increased in R&B, pop, and country songs. All genders showed an increase in theuse of anger-related words. In the rock genre the lyrics of older songs tend to be read more than recent ones, while in the country genre the exact opposite occurs.